10 Weirdest Fish in the World: Batfish, Hairy Frogfish, and More

Is this red-lipped batfish the weirdest fish species? We'll ask you to hold your judgment until you've seen the full list. Joe Dordo Brnobic / Shutterstock

Earth’s oceans are home to some seriously strange swimmers. From fish with transparent heads to bottom dwellers that pack an electric punch, the weirdest fish in the world come in all shapes and sizes.

From venomous spines to expandable stomachs, these strange swimmers showcase the extremes of evolution. Whether they hide in the sand, walk on fins or flash red lips, the weirdest fish in the world remind us that the ocean is full of surprises.

These species defy expectations with bizarre body shapes, extreme adaptations, and downright alien behavior. Let’s dive into the weirdest fish that roam the world’s oceans.

1. Barreleye Fish

This deep-sea fish is best known for its transparent head and upward-facing eyes. Found in the cold depths of the Pacific Ocean, its sensitive eyes can rotate inside its skull, allowing it to track potential prey above.

It survives in total darkness, feeding on small invertebrates floating in the surrounding water.

2. Goblin Shark

Often called a living fossil, this deep-sea shark lurks in the western Pacific Ocean and other deep waters.

It has a long, flattened snout and a jaw that shoots forward to snatch unsuspecting prey. Its fang-like teeth and eel-like body make it one of the most unusual creatures in the ocean.

3. Red-lipped Batfish

Found near the Galápagos Islands, this bottom dwelling fish uses its modified fins to "walk" along the ocean floor.

Its most striking feature? Bright-red lips that look like they came from a makeup kit. It doesn’t swim much and feeds on small invertebrates.

4. Fangtooth Fish

Despite its small size, the fangtooth fish has some of the largest teeth (proportional to its body) in the ocean. These fang-like teeth help it catch other fish in the world’s darkest environments.

It thrives in deep waters, though it is still preyed upon by larger fish such as tuna, marlin, and sharks.

5. Frilled Shark

With an elongated, eel-like body, frilled gill slits along its throat, and rows of needle-like teeth, the frilled shark looks more like an eel than a fish.

It lives in deep, isolated waters and is one of the most ancient shark species still alive, having changed little for about 80 million years.

6. Stargazer Fish

This venomous bottom dweller buries itself in sand with only its eyes and mouth visible. It can deliver an electric shock (around 50 volts), which serves primarily as a defense against predators rather than to stun prey.

Found in tropical and subtropical waters, its upward-facing eyes and powerful jaw make it one of the ocean’s creepiest ambush predators.

7. Hairy Frogfish

Covered in fleshy, hair-like appendages, the hairy frogfish blends into coral reefs with expert camouflage. It uses a lure attached to its dorsal fin to attract small fish and other invertebrates. It can also change color to match its environment.

8. Giant Oarfish

The largest species of bony fish, the giant oarfish can reach lengths of up to 36 ft (11 m). This elusive deep-sea fish has an elongated body and ribbon-like fins.

It lives in deep, open-ocean waters worldwide (including the Atlantic and Pacific) and is rarely seen near the surface

9. Asian Sheepshead Wrasse

This coral reef fish is known for its unusual appearance, including a bulbous forehead and flat face. Native to the western Pacific Ocean (coastal waters of Japan, China, and the Korean Peninsula), this wrasse is not commonly kept in aquariums.

10. Psychedelic Frogfish

Found in the waters of Indonesia, this rare species features a swirling pattern of bright colors and a bizarre body shape. It walks using modified pelvic fins and relies on ambush tactics to snatch prey. It’s one of the most colorful and strange fish known to humans.

We created this article in conjunction with AI technology, then made sure it was fact-checked and edited by a HowStuffWorks editor.