Fire-Belly Changeling is a common Creature — Shapeshifter card from Duel Decks: Knights vs. Dragons (DDG), collector number 51. Current market price: $0.22, TCGplayer market prices via Scryfall.
Changeling (This card is every creature type.) {R}: This creature gets +1/+0 until end of turn. Activate no more than twice each turn.