What could've been a former mascot-wearing employee, Wally is now a tortured, mutilated man begging for death and acting as the God of a small village, bestowing meals whenever requested by the voicebox.
Wally is probably the most difficult mandatory boss in the entire game- The only harder bosses are optional, those among the ranks of Beady and Satan (Unless you're playing on Pain Mode, in which case the forced battles against Herb and Hawk may give Wally a run for his money). Wally is divided into three phases: One, where his mask is perfectly intact, the second where his mask is cracked, and the third where parts of his mask have broken off revealing red flesh. He has 19,000 total HP through all three of these phases (For comparison, Peter has 17,000, Beady has 20,000, and Satan, the game's superboss, has 80,000) as well as an attack power that ties with Peter for second place in the enemies with the highest attack- 500 (The previous two phases have 400 and 130 ATK respectively). Wally is also one of the only enemies in the entire game that can inflict Depression, a crippling status debuff, and the move that does so targets all players and has a chance of inflicting Scared as well. He even sports a resistance to Fire in his early two phases (Fortunately he loses it for his third), is for the most part completely immune to Stun, and just to top off your Wally sized Painful Burger, in his very last phase he has a small chance of using Neck Break, meaning you risk loss of life when you face Wally. Facing this enemy early on in Area 2 is highly discouraged.
Wally's mask will crack and pieces of it will break off as the battle rages on, although his entire face is never seen, though the edges are shown to be a fleshy red texture similar to raw hamburger meat. When his mask breaks open he learns the move Neck Break. Caution is advised at this stage in the battle.
His laughter can be heard out the small village very faintly.
It's possible that his skin has been rotting inside the costume, turning his flesh into disgusting red skin (This may also be the source of the meat he gives to the members of the village).
Wally's laugh is sampled from the movie "Top Gun". The sound file is a distorted version of Goose's laugh from the movie.
One explanation for his fleshy red skin could be that he was mutating inside the costume, causing the outer layer of his skin to fuse with the material of his helmet. As the fight progresses, pieces of his helmet break off, and as the helmet breaks off, it tears skin along with it revealing the bloody inner layers of his flesh.
Once Wally is killed, the intercom at the bottom of the mountain will no longer be interactable and all of the followers of Wally will disappear. The men inside of the cave to Wally's, however, do not vanish.