Grim Matchstick bears an appearance similar to a typical dragon character from the game's time period.
He is a large, slightly chubby, European dragon with a very simple design. He has lime-green scales and a light-amber underbelly (lacking segments) that starts of at his distinct, beak-like muzzle. He has large pie eyes, no visible eyebrows (minus an indentation) and featureless ears on his head.
Grim has two large fangs resembling buck teeth and has a tongue that can extend like that of a frog, allowing his flame minions to walk across (similar to the famous red carpet method).
On his shoulder blades, he has average-sized, bat-like wings, the same color as his scales, that are flexible and can shape into arms (similar to actual bats), as seen in his intro, where he forms them into hands with fingers. His limbs are rather small and stubby, with four fingers on each hand, two toes on each foot, and silver claws/talons. He also has solid-white spikes running all the way down his spine (like many other dragons in popular culture), and he has a very long tail, which he uses like a baseball bat to swat his victims away.
When Grim reaches his third phase, he grows two more heads on his shoulders that look exactly the same as the original's head, which morphs into a red flame-thrower with a gold gas sprayer and lighter just in front.
Grim Matchstick is quirky and goofy, being more like a giant, overly playful dog, just as likely to hurt you while trying to play as he would be apologetic after his folly. He strives to spook people, making "ghostly" motions whenever the battle commences. He also stutters when speaking, as shown by his death screen lines.
Interestingly, Grim is one of the only two bosses (the other being Ollie Bulb) in the game that doesn't actually want to hurt Cuphead and Mugman. He views himself as misunderstood and apologizes for being forced into putting the brothers in a hot seat if they lose to him in his second phase. He even suggests that the brothers should run away from him after he turns into a hydra in his third phase.
The battle takes place in the cloudy area above Grim's tower where there is no ground to suppress any kind of fall damage, and the clouds are constantly flying to the left side of the stage, forcing the players to jump between them. In Simple mode, the clouds move slower. In Expert mode, the clouds fly to the right side of the stage instead of the left. Grim Matchstick introduces himself by making a spooky gesture with his wings and face, possibly in an attempt to look scary or intimidating.
"Don't m-m-m-misunderstand my flames -- I just meant fun and games."
—Grim Matchstick, Phase 1 Death Screen
In this phase, Grim mostly stays to the right side of the arena and damages the player/s with these attacks:
- Grim shoots ripples from his eyes, which consists of 3 ring-like projectiles, 4 after losing some health, at the players. The final ring of the beam can be parried. In Simple mode, the ripples travel slower. In Expert mode, they travel faster. In Simple and Expert mode, the "post-damage threshold" version of this attack is never fired.
- He can shoot large fireballs that travel in a wave pattern. He sometimes shoots two at the same time that crisscross each other, but only does this when he reaches a damage threshold. In Simple mode, their fire rate and speed is slower, and the "post-damage threshold" version of this attack is never fired. In Expert mode, their fire rate and speed is faster.
Grim always starts with the "Eye ripple" attack. However, in Simple and Expert mode, he can start with either of the two attacks.
He also uses his tail to attack by jabbing at the player(s) from the bottom of the screen. Getting hit by his tail can be avoided if the players pay attention to the bottom of the screen and the sound of the attack, which is the sound of his tail wiggling. In Simple mode, the tail has a longer delay before attacking.
After taking enough damage, he will slowly disappear from the right side of the screen and fly over to the other side, which can be seen in the background. He later appears on the bottom left and commences the second phase of the battle. Hitpoints = 660/629/684
"Sorry, I didn't mean to put you in the h-h-h-hot seat..."
—Grim Matchstick, Phase 2 Death Screen
In this phase, Grim will send out a parade of marching fireballs that travel across his tongue, which he stretches out as a platform. The leader fireball and the grouchy fireballs do not jump and simply act as an obstacle. The grinning fireballs will jump either directly towards the player or to the right side of the screen (no matter the location of the player/s) in an arc trajectory, and try to damage the player(s). The fireballs will crouch facing left or right before leaping, telegraphing where they are going to jump. If the player stays to the left, or only dodges fireballs by jumping left, they will rarely have to worry about fireballs jumping in a random direction. In Simple mode, the grinning fireballs jump less often. In Expert mode, they jump more often. Grim also shoots out smoke or fire from his nose. This will obviously damage the player(s) if they run into it.
After taking enough damage, Grim will retract his tongue with a beaten up look as his eyes bulge out of his head, then promptly rears up and grows two more heads, becoming a three-headed dragon, as he laughs mockingly. Each of his heads makes comical laughing expressions and the background turns into a rainstorm. In Simple mode, however, he won't retract his tongue nor grow any extra heads and the battle will end instead. Hitpoints = 540/510/551
"One..two..three! You'd b-b-b-etter flee!"
—Grim Matchstick, Final Phase Death Screen
In the final phase, players now face a three-headed Grim in a rainstorm. Grim, along with his two other heads, shoot about 6 to 9 cluster fireballs at the player/s, which can be destroyed but clustered into four directions in a plus formation. Hitpoints = 5/5
After shooting a number of fireballs, Grim's middle head will morph into a flamethrower (if observed closely, it is the original head) and fire a stream of flames that go right down the middle of the screen two times in three seconds before returning to normal and repeating the same process.
Once he has taken enough damage, Grim will be defeated with X marks his eyes, a hanging tongue, and drooped ears on all three heads. Hitpoints = 561/665
|Grim Matchstick activating and deactivating his peashot mode.|
|Grim Matchstick coughing out meteors.|
|Grim Matchstick using his tail for attacking.|
|Grim Matchstick dashing through the sky.|
|Grim Matchstick snorting out fire.|
|Grim Matchstick snorting out smoke.|
|Grim Matchstick's transformation.|
|Grim Matchstick defeated.|
|Normal Mode||Expert Mode|
Grim Matchstick was named after the legendary lead animator of Snow White, Grim Natwick, with his stutter also being a direct reference to Natwick. His little, stubby arms and legs are a reference to the dragon depiction from Felix the Cat's Woos Whoopee.
- Grim's first name "grim" means forbidding, uninviting, and/or morbid. Ironically enough, Grim is essentially the opposite of his name's true meaning in terms of physical appearance and personality.
- While not apparent at first, his appearance is ever so slightly reminiscent of that of Elliott, the bubbly, sweet-natured dragon from the classic 1977 Disney film, Pete's Dragon (released forty years prior to Cuphead), and it's remake from 2016 (released a year before the game's debut).
- Both dragons have a mainly green color palette (emerald-green for Elliott, lime-green for Grim), small, cow/deer-like ears, average-sized, bat-like wings on their shoulder-blades, and are rather chubby in appearance (although Elliott's stomach is bigger than that of Grim's).
- The similarities are more apparent in his remake counterpart, specifically his physical appearance and the scenes leading to the climax, as well as in the original.
- In the original film, Elliott fights off Dr terminus, Hoagy, and the Gogans to defend himself and Pete from getting seperated, captured and/or killed. And in the remake, he fights off Gavin and his many accompanies to prevent himself from getting caught for their personal gain.
- Similarly enough, Grim spends the entire battle fighting off Cuphead and Mugman to defend himself, his soul, and his contract.
- However, despite the similarities, Elliott and Grim have a good deal of differences between one another, in terms of physical appearance and their abilities, while only their personalities are almost the exact same.
- Elliott has a very large chin, a mint-green, segmented under-belly that begins only under his jaw, tufts of pink hair on his head, ears, and tail, and forest-green spots on his body. He also lacks the ability to grow more heads or shoot eye ripples (although his eyes are seen changing color often) and he is incapable of speech (minus several animalistic noises such as clicks, scats, and growls). He also can become invisible, his fire-breathing is much more realistic, and he (most likely) has bright blue eyes.
- Grim, on the other hand, has a more beak-like muzzle with (presumably) no chin with a light-amber stomach that starts on his muzzle and lacks segments, he has no spots on his body, and is completely hairless. He is also able to talk (complete with uncontrollable stuttering), grow spare heads, shoot eye ripples (similar to hypnotism), and his fire-breathing is far more cartoony (considering the old-times style of the game itself), complete with a parade of literal fire people. He also can't make himself invisible and apparently has no genuine eye color.
- Grim's personality matches that of the Dragon from The Reluctant Dragon, as both characters are wanting to prove that they are friendly and yearn to gain acceptance into society among their peers.
- He also bears a resemblance to Taro from The 7th Voyage of Sinbad which is one of the creatures animated via stop-motion by Ray Harryhausen.
- Grim's facial stucrture, complete with a pointed muzzle, bears a small resemblance to that of Maleficent's dragon form the 1959 Disney film, Sleeping Beauty.
- The fight is similar to the Mecha Dragon boss fight from Mega Man 2.
- Grim's second phase has fireballs with legs coming out of his mouth. These fireballs are possibly a reference to the similar-looking fireballs seen in Mickey's Fire Brigade and Elmer Elephant as well as Bimbo's Initiation.
- His final, three-headed form is presumably based off of King Ghidorah from the Godzilla franchise or the Hydra, a three-headed dragon from Greek mythology (though it is said that the Hydra have more heads than three depending on some interpretations of the mythology).
- In terms of old cartoons, Grim Matchstick's final form is based on The Calico Dragon from the 1935 cartoon of the same name.
- The rainstorm in the 3rd phase was reportedly influenced by the storm scenes in Disney's The Mad Doctor and The Old Mill.
- In the Old Testament, one of the stories describes a young Moses touching a plate full of embers and then sticking his hand in his mouth to cool it, causing him to scorch his tongue. Since then he heavily stutters, which might be a distant reference to Grim Matchstick's stuttering since he breathes fire.
- Grim's stutters may be also similar to Toothless, who is also a stuttering green dragon from the book series How to Train Your Dragon and its 2010 film adaptation from Dreamworks animation (in which Toothless never speaks and is black instead).
- Like his namesake, Grim Matchstick shares the same stutter with Grim Natwick.
- His last name is likely a pun, as matchsticks are used to create fire.
- While not exactly apparent at first, the music of his level "Fiery Frolic" as well as its name, actually holds a couple interesting pieces of symbolism regarding dragon-related culture.
- The music itself, if listened to very carefully, is found to have a strong hint of having a medival-esque style to it, much like something from a medival-fantasy story. This is apparently reminiscent of how dragons are said to have been greatly associated with the middle ages, a time when they have been said to cause great havoc or evil among many of their victims (as many fairy tales take place during that period).
- The battle's title "Fiery Frolic" is a heavily-implied reference to how dragons are known for breathing fire like blow-torches, and how they clearly have mainly "fiery" (hot-tempered or aggressive) personalities. "Frolic" is possibly reminiscent of how dragons tend to "frolic" (play around, often out of mischief or evil), which causes trouble in the societies in which they reside near or within.
- In the introduction to the fight, Grim Matchstick is seen using his wings to make a spooky gesture, rather than his hands.
- Grim's design is a reference to the dragon in The Twisted Tales of Felix the Cat.
- The castle in the background of the fight is actually a real-life model.
- Grim was one of the few sample bosses playable on the 2015 Demo.
- In the 2017 demo, Grim was the only one having no comment about the player's death.
- Originally, Grim fired different colored balls from his eyes instead of the rings he shoots now.
- The player can skip his final phase when doing enough damage to finish him, ending him on his third stage knockout instantly without any transformation.
- In the intro for the final phase, one of Grim Matchstick's heads has two mouths, which is most likely an animation error.
- The splitting fireball in the final phase has three different way to split, the in-game version where it split in all four directions and the other two split in left/right and up/down, the latter two were scrapped very quickly as only the left/right way to split is programmed but the up/down way wasn't even programmed.
- The Meteor Grim shoots in the first phase has an unused behavior that it shoot straight forward at a really slow speed instead of a sine wave.
- In an interview, it was revealed that Grim Matchstick's 2nd phase was originally going to turn him into a tambourine and the fireballs would be replaced with music notes, but this idea was scrapped because they agreed that it didn't make sense.