An Australian woman received an unwelcome surprise when she went to the washroom without the lights on and was bitten by a large snake inhabiting the toilet.

Helen Richards was staying with her sister-in-law in Brisbane’s Chapel Hill suburb earlier this week when she visited the washroom. She said she felt a “sharp tap” accompanied by a “bit of pain,” which she initially attributed to a frog.

“I jumped up with my pants down and turned around to see what looked like a longneck turtle receding back into the bowl,” she recalled to the local daily paper The Courier Mail.

As it turns out, the unexpected guest wasn’t a frog or a longneck turtle, but a 1.6-metre long carpet python.

According to a Facebook post by the snake-catching company that responded to the incident, the python was just as frightened of Richards as she was of it.

“Unfortunately, the snake's preferred exit point was blocked after being spooked by the customer sitting down and it simply lashed out in fear,” Snake Catchers wrote. “It showed no defensive behaviour after this point.”

The company said one of their snake catchers arrived at the scene with first aid so the woman could clean the small puncture marks left by the snake and spray antiseptic on them. Snake Catchers said it was fortunate that Richards didn’t flush the toilet after the incident because that would have likely caused the python to retreat down the pipes again.

“The snake was safely removed and relocated, and the customer handled the situation like an absolute champ, having a sense of humour about it the entire time,” the post read.

Snake Catchers said that although they don’t see snakes in toilets every day, it’s still a “regular occurrence.” However, the company said it was the first time they had encountered a customer with a bite from a snake in a toilet.

The reptile company advised people not to poke or prod a snake if they find one in their toilet. They also reminded people not to flush the toilet, either.

“Put the lid down, secure it, and call a snake catcher,” they wrote.

As for Richards, she wanted to warn others to “peek before you leak.”