Bosses appear after reaching a low enough point in The Pit. Bosses are more threatening than normal enemies, with more HP and attacking potential. Bosses are always accompanied by a siren, the same one that's played at low health, which stops when no bosses are present. Bosses always drop a unique red lightning bolt shaped pick-up , which flies towards you as though you had Attract Mode, and heals one health. Bosses will never go off-screen like normal enemies, and will follow you down. While bosses are present, more Star Plants will appear. As you go further down, more bosses can show up at once and the time between arrivals is shorter.
Generator BossEditFlies towards you constantly. Emits white sparks and black smoke, which do not do damage. Destroys blocks by making extended contact with them. Contour blocks are destroyed quickly. Full and Spike Blocks take a half of a second to break. Cannot destroy pick-ups.Takes double damage from non-star attacks.
MegadrillerEditComes from the top of The Pit, unlike other enemies. While falling, it destroys blocks, pick-ups, and enemies. Pick-ups and enemies are destroyed without stopping. Contour Blocks reset its downward momentum. Full and Spike Blocks take a half of a second to break. After breaking a block, it leaps upwards and towards you. Cannot break blocks going upwards. Only the top can be damaged. The drill does not destroy thrown stars, allowing you to attack from below.
Scuttles, trying to get you in its line of fire. Stops to fire bombs orthogonally towards you. Cannot pass through blocks. Bombs explode on contact with anything, and can destroy blocks, enemies, and pick-ups. Occasionally fires in all 4 directions. Bombs are treated like enemies, and can be interacted with by Snapping, Virus, and Evolving Enemies.
Insect BossEditCrawls around, staying near walls and away from you. Periodically stops and fires 2-6 red projectiles which can destroy pick-ups. If you get too close it will attempt to go to the other side. It can pass through blocks, but unlike other bosses cannot destroy blocks.