A five-foot iguana with an attitude is on the loose in west Edmonton.

His name is Gaylord.

The tropical reptile was basking in the heat of his Webber Greens backyard three weeks ago when — in a flash of grey-and-green scales — he climbed the fence, jumped the gate and vanished from sight.

As temperatures begin to plunge, his owner is becoming more desperate to find him.

"I'll do anything to get him back," said Mary-Ann Holm, who offered a $500 reward for the return of her beloved lizard. On Friday, with Gaylord still on the lam, Holm increased that reward to $1,000.

"He's kind of a big guy. He's kind of a fat guy, but I imagine not so much anymore. They need heat to have an appetite and to be able to digest, so if he's cold, he won't be eating."

"I'm out every day with my binoculars, scanning what I can see. He could be out sitting on somebody's deck or sitting in some shrubs, but I can't go into everybody's backyard."

Gaylord

Gaylord often roams about his backyard, basking in the sun. He scaled the fence three weeks ago and vanished.

 Anyone with information on the lizard's whereabouts is asked to send their tips to Holm directly.

If you do encounter Gaylord, be aware, he may be a bit cantankerous, especially after a few weeks in the wild.

"He's standoffish to people," said Holm

"If someone tried to pet him, he would like to walk away. He might flick his arm at them. He might be more prone to whip his tail, but he likely won't bite anybody."

The day he went missing, Gaylord was sunning himself in the grass, along with his fellow iguana, Fluffy, a bearded dragon named Beatrice and Pablo the tortoise.

'I just got a new dog earlier in the week. And that seemed to send Gaylord over the edge.' - Mary-Ann Holm

"As a rule, any time the weather is decent, I let them go out into my backyard, which is fully secured," Holm said.

"And I've been doing this for years. They sit out there and bask on the deck and go down and eat some dandelions, and scratch on the door when they want to come back inside. And I've never had an issue."

Reward offered for return of lost lizard1:13

Holm suspects her boxer, Ginger, may have served as the inspiration for Gaylord's big escape.

"I just got a new dog earlier in the week. And that seemed to send Gaylord over the edge. That day, I thought it would be good for him to go outside and have the dog outside, so they could get to know each other a little better.

"And she really wasn't trying to touch him or do anything to him, but just the sight of her flipped him out."

In retrospect, Holm thinks Gaylord may have been abused by a dog once, because part of his tail was missing when she rescued him.

Within 10 minutes of the lizard's disappearance, Holm and a contingent of neighbours were scouring the neighbourhood. But after three weeks, there has been no trace of the runaway reptile.

"All hope isn't lost, but as each day goes, I'm feeling less and less hopeful."

Fluffy

This is Fluffy, Gaylord's fellow rescue Iguana. They often spend their afternoons in their Webber Greens backyard. (Supplied )