Grim Matchstick is a hero and boss in the 2017 shoot 'em up Cuphead. He is a large dragon that can be found in Inkwell Isle 2 in the level "Fiery Frolic".
Although his size is quite intimidating, like most bosses, he is not in fact evil and is only an antagonist because he is trying to protect his soul from landing into the hands of the Devil.
Grim Matchstick is a large, green dragon whose design resembles typical dragons of European folklore. He has a long, yellow snout, a long neck, large pointed ears, green wings, and white spines on his back. Despite his size, he has notably small arms and legs. During his second phase, Grim Matchstick is revealed to have a long, snake-like tongue.
It his shown in his third phase that he is capable of sprouting multiple heads from his body.
As with most typical dragons in folklore, Grim Matchstick intends to scare his enemies with his large size and his fire-breathing, as evidenced by his intro at the start of the battle. However, while ferocious to his enemies, he is notably gentle and kind to his friends.
His dialogue in the game over messages shows that he stutters when he speaks, repeating a single letter on keywords. The dialogue also suggests that he was maybe pacifistic, as he didn't want to intentionally battle Cuphead and Mugman at first, a trait shared with Weepy the Onion of the Root Pack and Cala Maria during her first phase.
Grim Matchstick's fire-breath is also capable of spawning sentient fireballs, as evidenced during his second phase.
Grim Matchstick is one of the hardest and most frustrating bosses encountered by the brothers.
At the beginning of the battle, Grim Matchstick will enter from the right side in a spooky fashion, with his arms extended and his mouth motioning an "OOH".
During the first phase of the battle, Grim Matchstick will fire telepathic rings from his eyes in a series of 3 or 4 rings, one of which will always be parryable. At the same time, he will alter his attack pattern between firing the rings and firing fireballs that will travel in wave-like motions, sometimes shooting two at once. He will also occasionally use his tail to sneak attack the brothers at random.
The brothers must always be aware of the moving clouds on the arena, for if they fall out of the field, they will take damage.
Once he takes enough damage, Grim Matchstick will leave, fly from right to left in the background, and then enter on the left side of the arena. He will open up his mouth and release his tongue, which will begin spawning a (seemingly endless) parade of sentient fireballs, thus beginning his second phase. The brothers will need to watch out for fireballs that have evil grins on their faces, as those ones will jump at them. They must also avoid getting too close to Grim Matchstick, as he spews out fire from his nostrils.
Once he has been damaged even further, Grim Matchstick will then spout two additional heads from his body, an action that also causes the weather to change simultaneously from sunny to stormy. During this phase, the three heads will continuously fire out cluster fireballs, which can be destroyed, but will cause these fireballs to split into four pieces and travel in a plus formation. After firing a certain number of the fireballs, the middle head will then transform into a flamethrower and spew out a spring of fire at the brothers. The attack pattern will continue to repeat until Grim Matchstick is defeated.
Once defeated, all three heads will drop their tongues, and their eyes will have X-shaped pupils. Afterwards, Grim Matchstick will sign his respective soul contract.