DENVER — It’s perhaps the last thing you want to see boarding your local bus route: A python draped around a passenger’s neck, who is trying to pass it off as a “service animal.”

But RTD says scenes like this are becoming more common. In the past month alone, people have tried to board with snakes, a tarantula and a ferret. All of them out of their cages and in an owner’s hands.

RTD’s simple message: Stop.

“These animals do not qualify as service animals,” says RTD’s ADA manager Ed Neuberg. “They cannot be trained to perform a service or task.”

RTD does not allow “emotional support” or “comfort” animals, but it does allow service animals.

Federal regulations mean only dogs and mini-horses can be used as legitimate service animals.

“These animals are usually very well under control. They’re calm, submissive, and they’re paying attention to their handler.”

Neuberg says the increase in fake service dogs (and other animals), is making it more difficult for those who genuinely need them, like Michelle McHenry Edrington.

“Edgar is my service animal, we’re never apart,” she says of her dog Edgar.

McHenry-Edrington is a veteran who relies on Edgar to help with her PTSD.

“He can smell a change in my brain, when something is going to happen, or a trigger is near. And he’ll get my attention to break that cycle of the PTSD.”

She says people trying to pass of their pets as service animals is a constant struggle she deals with.

“I get accosted a lot because of stuff other people have done,” she says. “It’s very frustrating, because it causes a problem for people that have official service animals.”