The strange creature was spotted by a man filming at the bottom of the ocean in Bali – and some viewers were struggling to work out what it could be.

A perplexed deep-sea diver discovered a bizarre ‘alien’ creature with a translucent head and 13 legs at the bottom of the ocean.

(Image: Live Leak)

The bizarre animal appeared to have a big jelly-like ball in place of its head, which appeared to be loaded with spiky teeth.

(Image: Live Leak)

Its legs, which resembled tentacles in appearance, stretched perpendicular to its long, straight body, which appeared to be covered with small suckers.

The astonishing footage of the strange marine creature was captured by a diver in Bali, who had no idea what the alien-like fish could be.

(Image: Live Leak)

The odd creature can swim, doing so upside down by vigorously bending from side to side, touching its head to its tail

While it appeared to be from another planet, the creature was only a sea slug known as Melibe viridis.

Sea slugs can grow to be almost 12cm long, but their most remarkable feature is how they feed.

According to the Sea Slug Forum, the invertebrates catch their prey by using their translucent heads as a ‘oral veil’ – or fishing net.

When another sea creature touches the sensitive cells on the inside of the veil, it will contract rapidly, trapping the prey.

The strange alien-like creature is actually a sea slug (Image: Live Leak)

After the sea slug’s meal has been captured, it is then slowly ingested.

Unsurprisingly, viewers were perplexed by the monster, and it didn’t take long for them to speculate on what it could be.

(Image: Live Leak)

One man wrote: “I dunno, but I reckon if you threw it at a window it would stick.”

But another viewer was much more convinced: “This is a sea slug.”