The Jells were a race of bovine creatures from the planet Jelledge,that walked upright and were locked in often pointless conflicts with their planetary neighbours on Nabrili.
The Doctor brokers a peace between the two warring planets using a missile computer that he adapts by the addition of an electronic conscience (a spare part of K-9’s retrieved from the TARDIS) with the instruction that it was all the Nabrili’s idea. (DWAM: The Peace Strike)