Rockfish

A fisherman and his little alien pet go fishing on a desolate barren planet somewhere in the galaxy. With his gear he digs a whole in the crust up until the magma shows up. Now the fishing can start, some bait, and down the mechanical fishing rod goes. It won't take long until something eats the bait. But what kind of fish is this? One thing we know for sure: it doesn't want to get caught.