Would tortoise be the only answer? I know horses live like 30-40 years, but if I got one at birth I’d still be relatively young when it died.
And I’m talking realistic pets, no waterbugs or bears or elephants, Stampy excluded.
Parrots have pretty long life-spans. Macaws can live 50, or in some cases even 100 years.
Some parrots can live 85+ years.
shakes fist at badbadrubberpiggy
Some parrots have very long lifespans. Macaws, for example, can live past a hundred.
And I believe there are some fish which never grow old. They’ll live forever as long as conditions are right and nothing kills them.
Great. Now we’ve got a meme.
Some species of parrots can live to be 80 years old or maybe much older. You could get a Koi fish. If you take care of it, it can easily pass the 100 year mark or possibly over 200 years.
That’s the problem with the SDMB. We fight and disagree over everything no matter how mundane. Stop the controversy!
Get an elephant.
Humans are the longest-lived of the mammals, with only elephants even coming close. I think there might be some birds in the running, too, though, especially if you’ve already got a few decades on you.
Naw, memes only live a few years tops.
Awesome. I’m never the first one with the answer.
I feel so validated now.
Can you be more specific? The only thing I’ve heard of that has this particular trait was a type of shark. One of the ones on the larger end of sharks also, not a small “pet” or fun sized shark.
Or you could take an alternate route and get pet that only lives 20+ years, but you yourself live and extremely risky dangerous life, where your expected lifespan is less than that.
The tiny organ grinder monkey (Capuchins) live 40 years. Ross on Friends had one.
They are so tiny and cute.
Cheeta the Chimp is still going at around 75 years. There some doubt, however, that’s he’s the original Cheeta.
Some types of hydra and jellyfish appear to be immortal. Something a few millimeters long seems a bit puny for a pet though.
Yeah I knew of those and didn’t consider them anything near “pet worthy”. Though if you got a few dozen of them then maybe that would count. 
Blanding’s and perhaps also Midland Painted turtles don’t senesce—deteriorate physically—as they grow old. They simply don’t age. Pretty cool stuff. They’re endangered though, so it may not be a good idea to take one from the wild. Getting one that you could somehow breed, if you could provide a good habitat for it, may be allowed or worth it.
Enjoy,
Steven
Get a cobra and boop it playfully on the nose. It will outlive you.
Baby Midland Painted Turtle. The adults have pretty colorations too, but this pic rivals kitten and puppy pictures.
And this baby Blandings is well on its way to becoming the next teenage mutant ninja turtle.
Enjoy,
Steven