Plink

Plink was an alien who was defeated many times by the Doctor, each time by a different incarnation.

Among these incarnations was the sixth, travelling with Frobisher. Plink believed that that Doctor had a poor taste in clothes.

Plink joined forces with other aliens that had been defeated by the Doctor to try to kill him. He was caught in a three-way shoot-out and was shot by the Mentor, simultaneously killing Bolog. (COMIC: Death to the Doctor!)

Behind the scenes
In an interview with Jonathan Morris released in The Widow's Curse the description for Plink was given as; "an all-over body space suit, so his face — whatever that might be — is obscured by a breathing mask and a visor with three-eye holes. His space suit is very 80s, very Blake's 7 — gold-braided with shoulder-pads".