The lizard eventually rests when it gets to the top of the shelves, seemingly content with the chaos it has created.
The video which was shared about 6:40 am UK time has already been viewed more than 77,000 times and received more than 3000 retweets.
The massive reptile had climbed out of a nearby canal before crawling into the shop.
According to a follow-up tweet posted by the agency, water monitors are very common in the Bangkok area and other parts of Thailand and are very fond of carrion aka decaying animal parts.
Replies to the now-viral tweet are a mixture of shock and awe – with a few Godzilla jokes chucked in for good measure.
The unusually large creature is believed to have struggled to find food outside, following months of dry weather with little rain.
Asian water monitor lizards live in canals and ponds in large cities in Thailand where they feed on fish, snakes, frogs and scraps of food left by humans.
They are aggressive when threatened and have a mildly venomous bite which sometimes carries harmful bacteria.
Although they might look all cuddly and friendly, the lizards are to be handled with care as their sharp teeth can sever tendons and veins and they reportedly have a bite worse than a rattlesnake.