Prominent feature of a hippopotamus or crocodile

JAW

Think of the powerful part that snaps shut with incredible force in these river-dwelling creatures.

This clue points to "JAW" because both hippopotamuses and crocodiles are known for their massive, powerful jaws. The word "prominent" hints at a standout physical trait, and in both animals, their strong jaws are a defining feature—used for biting, defense, and eating. There’s no wordplay here; it’s a straightforward definition focusing on a shared anatomical highlight.