Fishliver Oil is a common Enchantment — Aura card from Ninth Edition (9ED), collector number 77★. Current market price: — (foil $3.78), TCGplayer market prices via Scryfall.
Enchant creature (Target a creature as you cast this. This card enters attached to that creature.) Enchanted creature has islandwalk. (It can't be blocked as long as defending player controls an Island.)