Hirasaka is pictured grimacing as he struggles hold the massive creature

Visibly straining as he holds it aloft, a Japanese fisherman grimaces as he proudly displays a terrifyingly large fish caught in the waters off Japan.

With a gaping mouth large enough to swallow a small child, this creature - believed to be a wolffish - would not look out of place in a science fiction film.

The massive catch was reeled in by Hirasaka Hiroshi, a fisherman who has made a career of landing and then eating unusual fish.

Hirasaka Hiroshi poses with the massive wolffish, caught off the coast of the Japanese island of Hokkaido

Caught off the coast of the island of Hokkaido, he said: 'It was worth flying to [Hokkaido] twice within three months. This guy is super cool,' the Daily Star reported.

Located just north of the mainland, Hirasaka said he landed the massive catch in the island's waters near Russia's coast.

Wolffish commonly live in the Pacific and Atlantic oceans. As deep sea dwellers, they feed on smallers creatures along the ocean floor.

The creature has developed a reputation due to its size and fearsome appearance and one type of the species featured on the Animal Planet series River Monsters.

Normally growing to about 1.2m in length, the wolffish Hirasaka caught measured close to two metres, The Sun reported.

The catch may also add substance to Japanese fishermen's concerns over the effects the Fukushima nuclear accident is having on local fish populations.

Normally growing to about 1.2m in length, the wolffish Hirasaka caught measured close to two metres

The Fukushima Daiichi nuclear power plant meltdown was triggered by an 8.9 magnitude earthquake in 2011.

The earthquake knocked out nuclear plant's cooling system, causing three reactor cores to melt and spew radiation into the ocean.

The earthquake - which claimed the lives of 18,500 people - caused what was the largest nuclear disaster since the Chernobyl meltdown in 1986.