Biobots

Biobots are robots which serve most villains and are the most recurring villains in both Ultimate Omnitrix 1 and 2 (In Ultimate Omnitrix, the bots only appear at Season 6).

Story
Biobots do not have feelings, they only seek to destroy who or what it's master asked. They were created by Atlas, a maniac doctor who plans to use them to conquer the world. However, the apparent leakage made from the Ninja Knight had led the villains raid the lab. The first to get all of them was the FOTO. The FOTO made some improvements like creating mind-controlling machines and all. Biobots and RNAliens can form into Bio-RNAts, a very powerful robot. More improvements are made in It's Elementally Controlled My Dear Gwen where Dr. Animo extracts DNAs from five aliens and add their powers into the Biobots.

Biodroid
A simpler version like Vilgax's Droids, they look like them, all one and the same

Avian Bots
TO BE ADDED