Eddie is one of our desert tortoises. If you don’t push the door shut all the way, he will open it and come in. Eddie is probably over 50 years old, and ours is at least the third house in our neighborhood he’s lived at.
Desert tortoises are a protected species and cannot be taken from the wild as pets. But they live a long time, and a long time ago they were not protected - so many people you meet who grew up in Southern California either had one in their yard or knew someone who did.
Captive torts cannot be returned to the wild, both because captive animals can introduce diseases to wild populations and because captive animals would be unlikely to survive being put back in the wild.
Eddie is legal now - registered with the CA dept of fish&wildlife. He has a burrow in our yard, and starting about now he will stop eating and brumate (brumation in cold-blooded animals is analogous to, although not exactly the same as, hibernation in mammals) until the spring.
Eddie was neglected by his previous owner, who had substance abuse issues. Before we took him in, he was left in a cardboard box and received no food for nearly a YEAR. When we got him he felt hollow, like a balloon, and could not walk.
But with care and time, he has fully recovered. He is an amazing animal. We will care for him as long as we can, then someday via the California Turtle and tortoise club (authorized by the state to handle tortoise adoptions) he may go on to yet another home.
Eddie is awesome.
Okay, several people had Eddie questions, so I'll add to this thread. Because, more Eddie. First, yes, Eddie is friendly -- I wouldn't say he likes to be petted like a dog or cat, but he's quite curious and always comes up to us when we're in the yard.
It's not always because he's hungry -- he is always curious about anything or anyone new in his yard. For instance, in this photo I was setting up a tent to make sure I had all the right parts before using it and Eddie... was not helpful. 
Eddie has come into our house many times over the years. Once we found him three rooms and a hallway away from the back door, all the way back in our bedroom closet sleeping among my wife's shoes. He's very stealthy.
Desert tortoises are vegetarians. We feed Eddie various chopped greens -- dandelion, collards, kale, plus he grazes a lot on the lawn, including "wild" dandelions and my extensive growth of crabgrass.
We don't feed him lettuce, as it's basically crunchy water with little nutrition. The only exception is when he comes out of brumation in the spring, when we give him a few succulent whole stalks of romaine lettuce for the water content.
Desert tortoises get most of their water from their food, since they almost never have the opportunity to drink in the wild, but they sometimes will if they can. Eddie likes to sip from our rare rain puddles.
Also, we almost never give him fruit -- desert torts aren't like box turtles, which will eat both fruit and worms/insects. Those things are not a part of a desert tort's normal diet. That said... all our torts love the nectar-filled jacaranda blossoms our tree drops each year.
Eddie is friendly and curious and happy to walk up to anyone. Desert tortoises are solitary animals except during the mating season, and males will fight. We have another adult male, Bob, who is bigger than Eddie and always tips him over. So they're kept separated.
Eddie's only other nemesis is our standard poodle, Charlie. Eddie has hated Charlie since he was a pup who mocked Eddie by being faster than him (see video from 7 yrs ago). Since then, Eddie has chased Charlie relentlessly, although Charlie has no idea he's being chased.
I guess I’d better give him his own hashtag #EddieTheTortoise
