Bigfoot has a circular metal head that has three eyes. On top of its head are small metal parts, and below its head is a small semicircle with three cannons attached. Attached to both sides of its head are it legs, legs capable of stretching. The thighs
are made up of metal segments connected with red ovals. The feet are wide so it can hold on to its long legs.
Bigfoot appears as the first boss in the game, as well as in the ending.
Bigfoot appears in the ending, where it lands with its feet between a resting Toxic seeing the view of the pool of Acid. Toxic then proceeds to destroy it. This proves at least more than one Bigfoot was created.
Bigfoot falls from the ceiling when the battle room is entered. Bigfoot will make big hops around the room. Harming it is simple, make it land in an explosion(s) of bomb(s). The more bomb explosions it is caught in, the more damage that is inflicted on the boss. When its health reaches a certain point, it will jump into the air and come back down, this time with the player between its legs. While in the air, it will move so that its feet are always on both sides of the player. The player can use this as an advantage and place bombs in certain places, so Bigfoot is hurt while moving.
It will make small movements in one direction with both feet, while the player has to make small movements also in the same direction. After some time, it will jump back into the air and land on the ground, this time hopping around. After sustaining more damage, it will use attack three, where it lands in the middle of the room and fires acid balls that travel on the floor in one direction. The player has to jump to avoid the acid. This phase leaves Bigfoot in a highly defenseless state, allowing the player to constantly lay bombs near its feet that can harm it, as well as avoid damage.
After sustaining more damage, Bigfoot will jump back into the air, and resume it hopping attack. After this, it can use absolutely any attack other than the one it last used. Destroying Bigfoot opens the exit door to the red teleporter, where the player may exit the level. Health cases are placed around the room for the player to replenish their health.
In the ending for Toxic II, when the man in the yellow suit takes off his helmet, a Bigfoot robot lands with Toxic between his two feet, meaning that there could be more then one Bigfoot robot made.
'Mother' is the leader of the factory, and it is said that she/it has control over all of the robots. However, she may not have control over Bigfoot since it appears in the very last scene of the ending, after Mother was already destroyed.
The boss is similar to Sidehoppers, an enemy from the Metroid series that perform very similar actions and has a similar appearance.