This is the shocking moment an aggressive monitor lizard charged into a room while a grandmother was sewing.

The pensioner was busy preparing pieces of cloth on the floor when the reptile entered her bedroom in Bangkok, Thailand, on July 1.

Footage shows the predator ambling on the ground.

Upon seeing the animal, the elderly woman screamed, startling it, and causing it to quickly run outside.

The homeowner shouted for her family to come help catch the lizard and get it out of the house.

Asian water monitor lizards normally live in canals, swamps, sewers and ponds in cities in Thailand. They feed on fish, snakes, frogs and scraps of food left by humans.

The reptiles are aggressive when threatened and have a mildly venomous bite which sometimes carries harmful bacteria. The Godzilla-like reptiles are also a protected species in the country so their population thrives.