Getting hit by his tail can be avoided if the players pay attention to the bottom of the screen and the sound of his tail wiggling. He also uses his tail to attack by jabbing at the player(s) from the bottom of the screen. In Simple and Expert mode, he can start with either of the two attacks. In Regular Mode, Grim always starts with the 'Eye ripple' attack. In Expert mode, their fire rate and speed is faster. In Simple mode, their fire rate and speed is slower, and the damage threshold never happens. He sometimes shoots two at the same time that crisscross each other, but only does this when he reaches a damage threshold.

He can shoot large fireballs that travel in a wave pattern.

In Simple and Expert mode, the 'post-damage threshold' version of this attack is never fired. In Simple mode, the ripples travel slower. The final ring of the beam can be parried.

Grim shoots ripples from his eyes, which consists of 3 ring-like projectiles, 4 after losing some health, at the players.

In this phase, Grim mostly stays to the right side of the arena and damages the player/s with these attacks: 'Don't m-m-m-misunderstand my flames - I just meant fun and games.'

Grim Matchstick introduces himself by making a spooky gesture with his wings and face. In Expert mode, the clouds fly to the right side of the stage instead of the left. 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. He also stutters when speaking, as shown by his death screen lines. He strives to spook people, making 'ghostly' motions whenever the battle commences. Grim Matchstick is quirky and silly, 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 is also the father of the 3-headed baby dragon that resembles him. In the The Cuphead Show!, Grim has three heads instead of one much like from Phase 3 of his video game counterpart's boss battle.

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. 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. His limbs are rather small and stubby, with four fingers on each hand, two toes on each foot, and silver claws/talons. 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. 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). He has large pie eyes, no visible eyebrows (minus an indentation) and featureless ears on his head. He has lime-green scales and a light-amber underbelly (lacking segments) that starts off at his distinct, beak-like muzzle. He is a large, slightly chubby, European dragon with a very simple design. Grim Matchstick bears an appearance similar to a typical dragon character from the game's time period.

Cuphead background