It's like something out of an animal horror movie -- killer frogs take over peaceful pond, then after terrorizing and eating everything alive, start eating each other.

Only it's no movie. It's really happening in Golden Gate Park's Lily Pond, near the California Academy of Sciences. And after watching the frogs chew through everything in sight over the past several years, the city finally wants to do something about it.

No one knows for sure when the African clawed frogs got into the pond or who put them there. But there they are, and the Toad Warriors have pretty much taken care of the native turtles, frogs and fish.

"They've eaten everything they can get their mouths around, and now they're eating each other," said Eric Mills of the animal rights group Action for Animals.

Mills worries that the fiendish amphibians -- which grow to 5 inches in length and have claws on the toes of their oversize hind feet -- may jump the pond and spread their reign of terror across other Bay Area waterways, although so far, none has popped up elsewhere.

"The fear is they will get out,'' said Richard Schulke, president of the city's Animal Control and Welfare Commission.

In 2003, the state Department of Fish and Game was going to drain the pond, but at the last minute, it pulled back. Fish and Game reps didn't return calls for comment, but Schulke said outrage over the department's poisoning of pike up at Lake Davis about the same time may have given the state cold feet.

Since then, park workers have used nets and traps baited with chicken to yank about 2,500 adult frogs out of the pond. The frogs are then sent up to Fish and Game in Yountville, where they are euthanized by a special nerve poison.

But the Terminator toads just keep coming back.

"They are cute, but tough," Mills said. "I saw a heron swoop down and grab one. He had it in his bill for a while, tried to eat it, then just gave up and spit it out."

In fact, about the only thing known to eat the frogs are crocodiles -- but that solution is probably out.

Instead, the city is thinking of stepping in where the state stepped back. Although they were warned the cost could be exorbitant, members of the Animal Control and Welfare Commission voted last week to ask the Board of Supervisors for money -- whatever it takes -- to drain the pond once and for all and send the remaining frogs to the big lily pad in the sky.

"I admit it's an unusual thing for an animal-loving group to do,'' Schulke said.

But hey, that's life in the food chain.

Burp.