Pookie is the name of Roy's pet rabbit in Nintendo Comics System comics published by Valiant Comics.
Pookie's only appearance in the comic series was the issue "Bowser Knows Best". Pookie can be seen on the first page of the comic, while the Koopalings are deciding what to get their father Bowser for Father's Day he can be seen in a small cage cowering from Roy who suggests perhaps simply beating Pooky would be suitable present for Bowser.
Roy ends up dropping the cage, which breaks allowing Pookie to escape when Wendy drags him away to help them capture Princess Toadstool. Pookie can be seen in the backround of a few pages after this.
Pookie later appears on the last page of the issue also, while Bowser is distracted reading a calender which Lemmy had written (rather poorly) "Be Kind to Turtle Kid Day" (a fake holiday made-up by Princess Toadstool) on. Pookie manages to escape by jumping out a window and disappearing into the night, it is around this time Roy realizes Pookie has escaped.