>>31882919I don't think abilities and moves are directly related to a Pokemon's anatomy. Certainly inspired by, but not directly a result of.
Pokemon are essentially magic, it doesn't have to make direct sense.
Sap Sipper could just be a special power that causes the Pokemon to absorb Grass typed moves. It doesn't necessarily mean it literally eats the move. Water Gun doesn't imply the Pokemon pulls out a supersoaker, and Guillotine definitely doesn't physically decapitate the enemy.