After an intense battle against a series of minibosses, the Mother Alien emerges as the first phase of one of the final bosses in the game. A grotesque monstrosity that resembles a giant female human face held by two equally giant alien hands, with what appears to be her brain (or a myriad of tumors resembling one) sprouting out from each side, giving it the appearance of a Victorian-era hairstyle.
She attacks by constantly unleashing repulsive-looking flying eyeballs, which themselves have more eyeballs inside. These float and home toward the player.
At the end of each side of her brain, two tentacle-like appendages with clawed hands come out which will be constantly shooting lightning bolts and attempting to reach the player throughout the battle. Their hands can be damaged and destroyed separately in order to destroy the whole limb.
The Mother Alien's deceitful serene expression will start twisting in a most horrible grimace every time she takes damage and soon her skin will peel off revealing an alien skull underneath still covered in tender skin. At this point, she will start bouncing from side to side in the background and the hands will gain the ability to unleash lightning bolts.
This large, humanoid alien performs a long chain of attacks. It starts by emitting an ocular heat ray along the ground and platforms for two loops clockwise; the ray leaves short-lasing flame trails.
Each of its arms periodically emit a sentient plasma orb. The boss then launches several pairs of red plasma orbs at the player which detonate into flames at their immediate location.
Next, it vomits acid a few times in a limited arc range that follows the player's direction. This pattern is then repeated but in the opposite direction.
The Mother Alien's head is its weak point.
This boss is not present on the Easy difficulty setting.
- The Mother Alien's and Master Builder's overall appearance and attack methods in conjunction resemble those of Emperor Demon Gava.