Tortoise owners in the US are facing a growing problem.
Families are buying tiny sulcata tortoises as pets, not knowing the reptiles can get to be almost a metre long and live for decades.
"Of all the tortoises I've worked with they have the most interesting, complex and best personality," says Owen Maercks from East Bay Vivarium.
But they do come with a big downside.
Tank is one such tortoise. He started out the size of a tennis ball and now weighs close to 110kg.
Sonoma County animal rescuer Al Wolf says Tank was surrendered 20 years ago at a mere 15kg.
The tortoises can live to be more than 100 years old and, Mr Wolf says, they can be a destructive powerhouse.
"They can break all your lawn furniture," he says.
It's a growing problem for the growing number of sulcata owners.
Some buy them impulsively online or at reptile shows, and don't realize what they're getting into.
"They eat the same thing a horse does and when it comes out the other end... it's the same thing like a horse," Mr Wolf says.
"Do you want to keep a horse in your house? No."
The American Tortoise Rescue says rescue groups average three or four calls a week from owners who want to get rid of their sulcatas, most often when they reach 20kg or 10 years old.
It's calling on the pet industry and breeders to stop selling sulcatas.
Mr Maercks says he will only sell these little guys for "educational or scientific" purposes only.
For every 100 customers who come in for one, "10 consider it and one may actually buy," Mr Maercks says.
The tortoises cost between US$50 (NZ$70) and US$100 (NZ$140), and in most cases zoos will not take them off your hands.