He appear as a giant, happy-looking maggot colored entirely in red. He sports with stubby arms, beady eyes, and a mouth with crooked teeth. He is also covered with multiple hair strings.
Like Chub, C.H.A.D. can charge at the player. While at first acting like its normal counterpart, C.H.A.D. shrinks in size and increases in speed as Isaac damage it. He spawns 2 Suckers throughout the fight.
When defeated, the Little C.H.A.D item will unlock if Isaac didn't have it. If Little C.H.A.D has been acquired before the C.H.A.D encounter either through the shop or the D6 C.H.A.D will drop an item from the normal boss loot table.
Eternal C.H.A.D. acts similarly to normal C.H.A.D.. But it also spawns Spits and always shoots 8-way bullets whenever it spawns the minions. It has health regen, but its size won't grow again as it regenerates.
Like Chub, placing a bomb while C.H.A.D. is charging towards Isaac will cause him to swallow the bomb, stopping him for a second and then causing an explosion, which deals severe damage.
C.H.A.D. appeared in the original game.
C.H.A.D. is a cameo from Super Meat Boy, another game by Edmund McMillen. In the actual game, he is the boss of Chapter 2: The Hospital.
The Caves is the second area in The Binding of Isaac, and so is the hospital in Super Meat Boy.
Once C.H.A.D is killed in Super Meat Boy, he shrinks down to a smaller version of himself. Dropping Little C.H.A.D mimics this.
The name C.H.A.D. comes from the old horror film C.H.U.D., confirmed by Edmund on formspring.
Along with Chub, the fact C.H.A.D eats bombs if he`s charging, could be a reference to The Legend of Zelda boss, King Dodongo.
His name could be an abbreviation for "Cute, Huge, and Deadly".
From the original game, C.H.A.D. is unlocked after beating The Caves 20 times instead of 30.
Using the Emergency Contact on C.H.A.D. and then killing him while he is held will cause the game to crash. ()