You have reached the bottom of the Tower and are now facing the death meatball himself, Teratomo

To defeat Teratomo you must pop the yellow zits all over his body. These deal the most damage to him but you can also shoot him in the eyes to deal slightly less damage. He has three main attacks he will use

Acid Spray: Each of the three big platforms in the back have acid sprayers above them. When teratomo reaches his arms in the sky, whichever one you are standing one, Run! he is about to cover it all in acid, making you unable to stand on it for a short period of time

Tentacle Slap: If you are standing close to Teratomo on any of the three small platforms in the center of the room, after a short amount of time he will raise his tentacles in the air, slapping each of the platforms at once. You will have a small window to jump off the platform and get out of there

Jellywaft Summon: The final thing Teratomo can do is spawn some jellywafts to damage you while you are trying to fight. These can be extra annoying when combined with the acid spray attack, as they will make moving from platform to platform much more dangerous. it is you best bet to take these out as soon as they spawn.

You can use bombegranites to destroy a bunch of zits at once on the left and right sides of his body because they are closely grouped together thanks to his giant size. Each time you deplete one of his health bars he will spit his tongue out and give you access to the inside of his mouth where the planet seed is located.

Walk inside his mouth to try to pull the seed out, get spit out, and do it again two more times. Once you defeat teratomo you will be successful in removing the seed...but uh..he may eat you. Luckily you uh...come out the other end.