Fish that can burrow into the seabed

EEL

This slippery swimmer might hide in mud but isn’t actually a snake.

This clue describes a fish known for its ability to bury itself in sand or mud, which fits the eel. While eels aren’t the only fish that do this, they’re famous for their snake-like bodies and habit of hiding in the seabed to ambush prey or avoid predators. The answer plays on the eel’s natural behavior rather than any wordplay—just a straightforward definition. Think of moray eels or garden eels, which are especially skilled at disappearing into the ocean floor.