The Ultimate Chimera (きゅうきょくキマイラ, Ultimate Chimera) is a creature from the EarthBound series, specifically Mother 3.
In Mother 3, the Ultimate Chimera is first encountered in the Chimera Laboratory in Chapter 7. Here, it is running amok and chases anyone who enters its line of sight, including Lucas and his party. It cannot be fought, as merely touching it on the overworld will cause a Game Over. When it spots Lucas in Mother 3, an exclamation point appears over its head and a distinct noise can be heard: the same sound is heard in Brawl when the Ultimate Chimera appears on the New Pork City stage.
The Ultimate Chimera is disabled by Salsa hitting the large button on its back; however, the bird on the creature's head revives it by pressing the button again. Later on, in Chapter 8, the Ultimate Chimera can be encountered again in the bathroom floor of the Empire Porky Building in New Pork City.
As a stage hazard
The Ultimate Chimera appears as a major stage hazard in New Pork City. Appearing randomly in any part of the stage, it walks slowly, stopping once there is a ledge to turn around. It attacks any fighters it encounters by biting at them. Its bite attack deals immense damage (100% if the player is by the edge of its mouth, and 200% if trapped inside) and extreme knockback, usually resulting in a one-hit KO (even considering the stage's large size). The Ultimate Chimera is functionally invincible; it can only be indirectly defeated if it walks over the makeshift bridge platform at the lower center of the stage and a fighter destroys the bridge, causing it to fall off the screen.
Oddly, unlike most stage elements, the Ultimate Chimera has no trophy in Brawl.
In Smash Tour
The Ultimate Chimera appears as red Trophy Item. When selected before a battle, it causes the user to take two fighters instead of just one from the last opponent they KO. It activates regardless of whether the user placed first in the battle.
The Ultimate Chimera trophy is part of the Mother Series Trophy Box.
As a stage hazard
The Ultimate Chimera returns alongside New Pork City. Unlike Brawl, it roars when it appears, allowing players that happen to be nearby to get away, and its chomp deals an instant KO instead of launching the fighter. The attack will also deal 120% damage, but the added damage will only appear for two frames before the instant KO occurs.