JAGRAFESS

The Jagrafess are gigantic, gelatinous creature similar to a slug in shape. They are sentient and able to communicate in a series of growls and screeches, with sharp, vicious teeth and several vestigial eyes. They have a life span of about 3000 years. Their metabolic rate forces them to be kept at low temperatures to survive. Hot temperature causes them to overheat and explose. Their exact origins are not known, but circa 200 000 AD, they were a servant race of the Daleks. It is possible that they might have been bioengineered by them.
Source: Doctor Who Universe, "The Long Game".