Gell Guard

The Gell Guards are a race of creatures made by the Time Lord renegade Omega as foot soldiers during his time in the anti-matter universe.

Biology
Completely composed of anti-matter, the Gell Guards appear like giant blobs of orange, bubble-like structures. The Gell Guards possess a single eye and a giant claw at the right side of their bodies.

History
The thought-to-be-dead Time Lord Omega created the Gell Guards completely out of anti-matter from the universe he resided in for centuries, where he was driven insane by the inhale on the anti-matter residing in said universe and began to seek revenge for his abandonment. While Omega could not return to positive-matter universe because of how the inhale of anti-matter rendered him composed of anti-matter, the Gell Guards were created to survive in the our universe of positive matter and were used to invade UNIT HQ (the current location of the Doctor) and take the Doctor back into the anti-matter universe.