Eel Oil is a product used for male hair growth. This product is made from eel slime for men to grow beards. Only Slippery Pete sells eel oil. No one knows if eel oil really does make people grow beards because when Flapjack bought it for Captain K'nuckles he said eels don't have hair. Cartoon Network made a commercial about it when a kid wanted a beard so he could be an adventurer.