The Cheetah Planet is a common Plane — Outside Mutter's Spiral card from Doctor Who (WHO), collector number 574. Current market price: $0.35, TCGplayer market prices via Scryfall.
When you planeswalk to The Cheetah Planet and at the beginning of your upkeep, put two +1/+1 counters on target non-Cat creature you control. It becomes a Cat in addition to its other types. Whenever chaos ensues, all Cats gain provoke until end of turn. (Whenever a Cat attacks, its controller may have target creature defending player controls untap and block it if able.)