Clam Session is a common Creature — Clamfolk card from Unglued (UGL), collector number 20. Current market price: $0.29, TCGplayer market prices via Scryfall.
As this creature enters, choose a word. At the beginning of your upkeep, you may sing at least six words of a song, at least one of which is the chosen word. If you don't, sacrifice this creature. You can't repeat a song.