This is the moment a hero pooch saves a lizard from drowning in a swimming pool.

Footage posted online by TikTok user Ayla Philippsen shows how brave pup Thor swims towards the huge reptile after noticing it struggling to climb out of the pool.

Thor’s owner can be heard shrieking in fear as the pet dog approaches the lizard and grabs it between its jaws.

The footage then cuts to Thor already out of the pool and dropping the lizard gently onto the ground a safe distance away.

But the reptile is apparently ungrateful at having been rescued and tries to bite the pooch several times on the muzzle as its owner screams once again.

Thor can then be seen barking at the lizard as if to tell it to go away.

Local media reported that the lizard probably thought the dog wanted to eat it and tried to bite it as a defensive reflex.

The clip was posted online on 26th December and has since racked up an astonishing 5.7 million views.

Ayla – who is from Goiania, Brazil, but lives in Sao Sebastiao do Cai – responded to worried netizens concerned for Thor telling them neither animal was hurt.

Once out of the pool, Ayla’s father collected the lizard in a box and released it back into the wild.