Emcee is a uncommon Creature — Human Rogue card from Unhinged (UNH), collector number 9. Current market price: $0.39, TCGplayer market prices via Scryfall.
Whenever another creature enters, you may stand up and say in a deep, booming voice, "Presenting . . . " and that creature's name. If you do, put a +1/+1 counter on that creature.