Pete is the main antagonist from the Red Dwarf episodes Pete I and Pete II. He used to be a sparrow, but the time wand then turned him into a Tyrannosaurus Rex.
History
At first, Pete the sparrow is Birdman's pet. When Birdman is put into the Hole as punishment for unspecified crime, Pete becomes his only companion till Rimmer and Lister are put inside, too. At the time Pete is nine years old, has a cold and sneezes a lot. When the trio escapes from the Hole, Birdman brings Pete with him in a small cage.
Unfortunately, Pete dies almost immediately because of excitement of being free from captivity. Birdman feels very unhappy, so Kryten tries to make Pete young and strong again using the time wand. However, he mistakenly turns back evolution by many million years, turning Pete into a Tyrannosaur Rex.
Now enormous Pete still has a cold and sneezes on Birdman. Hungry dinosaur then eats him, Bob the skutter and the time wand he is holding. Scared Boys from the Dwarf quickly hide while angry Pete rampages around the cargo deck. To get Bob and the time wand back, they prepare a cow vindaloo and lure Pete into eating it. However, it is too hot even for a dinosaur. Pete has a terrible stomachache which leads him to run off into the cargo bay, eating along the way all the ship's supply of mint-choc ice cream, orange ice-pops and fizzy drinks.
Meanwhile in his stomach, Bob is able to use the time wand to unfreeze everybody else on Red Dwarf. The crew then quickly finds out what is going on in the cargo bay. They send three platoons of troops against Pete, but the vindaloo he ate causes him to defeat all of them by massive burping, a vomit deluge and a big wave of diarrhea. There is also Captain Hollister in the third group, much to his dismay. Luckily, his group manages to sedate Pete, so he orders Lister and Rimmer to turn him back into a sparrow with the time wand which was released from Pete along with Bob.
When Lister finds sleeping Pete in the cargo bay, he uses the "undo" function to bring Birdman back to life and turn Pete into a sparrow. Pete is an innocent pet again and flies to Birdman for seeds. Rimmer, afraid of the time wand, forces Lister to destroy it. However, it is a big mistake, as Pete has already laid an egg (which means he is actually she). When a baby Tyrannosaur hatches out, it walks into Captain Hollister's massage room and starts licking his back, causing him to think it is just an assistant who makes him a massage.