C.H.A.D.

Overview

C.H.A.D is a boss from Super Meat Boy that appears as the end of the hospital in chapter 2. He summoned when Dr. Fetus attempts to flood the place with blood in an attempt to kill Meat Boy. His first appearance is after he explodes forth from the pipes supplying the blood. Not much else about him is known. What little official information is supplied by the developers, Team Meat, on their blog. They describe C.H.A.D. as a giant contaminated mass of blood and tissue that develops an attachment to Meat Boy at first sight.
 
It's not confirmed what his name stands for. The popular theory is "Cute, Huge, And Deadly".
 
Unlike most of Dr. Fetus' creations, C.H.A.D. has a wide grin plastered on his face no matter what he's doing. The sounds he makes are playful, making him appear to be more misunderstood than malicious. Either way, he can kill Meat Boy with a single touch. Sunlight has an adverse effect on him, shrinking him down in size.
 

Tactics

C.H.A.D. can only kill Meat Boy on contact. He spends most of his time splashing around the pool of blood at the bottom of the screen. This involves jumping in an arc from one side of the screen to the other. He can also pop up in the middle to cover the center of the area.   His pattern changes slightly after grabbing the first key, where he simply swims back and forth along the surface while flailing his arms.   The boss battle against C.H.A.D. is more of an obstacle course. After grabbing enough keys, the hospital roof will open and let enough sunlight in to shrink him, ending the fight.