- Kingdom: Animalia
- Phylum: Chordata
- Subphylum: Vertebrata
- Superclass: Gnathostomata
- Class: Actinopterygii
- Order: Syngnathiformes
- Family: Syngnathidae
- Scientific name: Entelurus aequoreus
- Norwegian: stor havnål
In contrast to many other pipefishes, the snake pipefish is incapable of changing color. The light brown, almost orange color and the white vertical stripes on its body is typical. The rudimentary tail fin contributes to its poor swimming capabilities. The dorsal fin is largely in front of the ventral fin. The length body length of the male and female may reach 40 and 60 cm respectively.
The snake pipefish is usually encountered just below the tidal zone, hiding among seaweed.
It is registered on Iceland and along the Atlantic coasts, from Troms, Norway to Gibraltar and Azores. It is absent from the Mediterranean.