The trust that looks after our canals and rivers is worried about ‘mutant Ninja turtles’ munching their way through wildlife along its waterways.

Hollywood’s ‘Teenage Mutant Ninja Turtles’ blockbuster on cinema screens this month could lead to fans buying mini turtles, or terrapins, as pets which might eventually be dumped in the wild when they get too big, the Canal & River Trust fears.

The previous Ninja Turtles craze in the 1980s and 90s led to thousands of matchbox-size baby terrapins being bought as cute pets, then abandoned when they outgrew domestic home tanks.

“They have been causing damage to our native wildlife ever since,” the Canal Trust’s ecologist Richard Bennett told the East London Advertiser.

“Baby terrapins are pretty cute, but can grow as big as a dinner plate and be pretty grumpy—and very smelly.”

Terrapins, which are native to North America, can live up to 40 years.

“We’re still dealing with the effects of the last Ninja Turtle craze 20 years ago,” Richard revealed.

“Hungry terrapins munch their way through our native wildlife such as dragonfly and damselfly larvae, frogspawn, small fish—and even ducklings. They harm the ecology of our canals and rivers.”

The trust is advising Ninja Turtle fans to research and understand what they take on and to get help from pet shops or animal charities about finding new homes for them if they are struggling to cope—but not release them into the canals.