Slime-Biot

Slimebiotes are a sapient genetometamorphic species who predate all other DNA-based life forms in the universe.

Anatomy
Slimebiotes resemble small green globs with tendrils. They have little antennae sticking out of their heads and their eyes are small and slit-like.

Diet
According to Khyber, Slimebiotes feed on DNA.

Powers and abilities
When attached to an alien, Slimebiotes can use the alien's DNA to create extra limbs. When attached to an Omnitrix-type device, they can use any available DNA sample to create weapons and tools for aliens of a different species, including Humans.

Slimebiotes are impossible to remove by force (except by ionic surgery), since they only leave their hosts if they choose to.

History
According to the Contemelia, Slimebiotes are the most important beings in all of creation as they carry, mix, and deposit DNA across new and growing universes.