Esther the Wonder Pig lives with her owners Steve Jenkins, left, and Derek Walter, along with other pets that live in the household. Fans say pigs are funny, smart and full of personality, but many wind up homeless when they turn out to be much more than the owner was expecting. Jenkins and Walter even wrote a story about her, “Esther the Wonder Pig: Changing the World One Heart at a Time.”

Pigs don't have the greatest reputation. The word is probably used more as an insult than as a reference to a real animal.

If you meet a pig, though, you might feel differently.

“People will come and volunteer with us and most of them have never been around pigs,” says Jen Reid, manager of Marshall's Piggy Paradise at Best Friends Animal Sanctuary in Utah. “They go away smitten.”

Their fans say pigs are funny, smart and full of personality.

So then why do they end up in a sanctuary?

Time and again it's the same story: “People say, 'We bought a pig a year and a half or two years ago, and the breeder told us it would not get larger than 40 pounds,'” Reid says. Then the animal grows to 150 or 250 pounds — or more.

That's what happened to Steve Jenkins and Derek Walter, whose Esther the Wonder Pig is now famous online. They've written a book (“Esther the Wonder Pig: Changing the World One Heart at a Time,”) about the tiny piglet who grew up to weigh 650 pounds.

Pigs are curious and strong. That became clear long before Esther was her full size.

“When Esther was about 250 or 300 pounds, she stuck her nose under the couch and lifted the whole thing in the air with us sitting on it,” Jenkins says.

Their jaw strength is just as impressive. When she was only about 100 pounds, Esther got into a cupboard full of canned goods. “She crushed those cans like they were butter,” he says.

Pigs can be house trained, but Walter calls their experience “memorable.”

“We were going through a rainforest worth of paper towels,” he says. “Imagine throwing 3 gallons of water on the floor — how many towels you'd need.” They tried to train her to use a litter box indoors, but eventually even a kiddie pool wasn't big enough. When they switched to outdoors, she tried to train them: She'd ask to go out constantly, pretend to pee, and then come running for her treat.

Having a pig in the house changed everything — and not just in the house.

Before Esther, “the house was immaculate, the yard was immaculate,” says Jenkins.

But one of a pig's fundamental needs is to root around in the dirt. “She didn't want to just eat the grass, she wanted to flip it over because she likes the roots,” he says.

If none of that puts you off and you're still passionate about having a pig, first check zoning regulations. If they define pigs as livestock and you're not zoned for livestock, your pet is illegal — as Esther was, in their first home.

Then, be very careful about what you're getting. Candace Croney, associate professor of animal sciences at Purdue University, says it is possible to breed pigs in the 40- or 50-pound range that some breeders claim to offer, but you should ask about the parents' size and the average adult size of prior litters.Be prepared to maintain a healthy weight for a pet pig. Many of those that come to Best Friends Sanctuary are grossly overweight. Remember, says Croney, that pigs are both very smart and genetically programmed to spend most of their day looking for food.“The ones that are really good pet pigs, that are offering us cute behaviors, will learn very quickly that that's how you get extra food out of people,” she says. And they tend to put on weight quickly.Having pigs with other pets can also be a challenge. Pigs are social animals, but their interactions are particular to their species.“They have little posturing, challenging matches — it's part of their innate behavior,” says Reid. “And what we see is that only other pigs can relate with them in the same way. When they start doing that with people it turns into aggression, and when they try it with dogs, either the dog can get hurt, or it prompts an attack from the dog.”Jenkins and Walter agree that caution is essential.“We've seen some sad and scary situations of pigs and dogs getting into fights,” says Walter. Esther is used to the dogs she was raised with, but she's not allowed to play with them. When she wants to, the humans intervene and redirect her to play with them instead.To meet pigs' social needs, Best Friends only adopts them out in pairs, or to homes where there is already a pig companion.“From what we've seen and experienced here, pigs do best when they have the opportunity to live with other pigs,” says Reid.

Esther the Wonder Pig wasn't supposed to grow large, but the once tiny piglet now weighs in at 650 pounds.