Gell guard

Abilities
Anti-matter creatures have the ability to travel from the world of anti matter into that of matter. They use their claws as weapons to fire blasts. They are immune to gun and rocket fire.

History
The Anti-matter monsters were sent by Omega from the world of anti-matter inside a Black hole to the world of normal matter, under Omega's command they attacked UNIT HQ. They killed a number of soldiers. In the world of Anti-matter a group of the creatures captured the Doctor and co. They took them to Omega's lair.