If you are looking for a place to get a free poptropica membership account you have come to the right place.
While I was looking for the same thing I found a website called FreeGameMemberships.com that gives away free memberships to anyone who earns enough points. I tested it out and it actually works but it takes about 10-15 minutes to get enough points to enough points to redeem a free membership code. (If you are really quick you could probably get enough points in about 5 minutes but it took me 10)
So basically there are a bunch of offers like free games to test or polls that you can do and they give you points for doing it. So a game like candy crush will give you 100 points for testing it and telling them whether it is a bad, ok, or good game. Then once you get enough points you can redeem it for a membership.
I mostly did polls because they only take about 30 seconds and 10 polls or so can get you a one month poptropica membership.
They also have 3 month, 6 month, and one year memberships too but they take a bit more points to get.
So if you want to get a poptropica free membership code that's the best site I have found online that actually works and isn't a scam. Most of the sites I found don't give memberships away but this one actually emailed me a code after I redeemed it with my points so I know it works.
Let me know if you know any better sites than FreeGameMemberships.com