there is no pet island on poptropica
There is no Pet Town Island. (it was a bogus answer)
you can get one on skullduggery island
Super Power island
You can not go to downtown
You could get a house on Poptropica. But not a pet. To get a house you could get a house on 24 Carrot Island! It's on the carrot farm. If you complete 24 Carrot Island... you have a mystery roomate! You go thru the chimney to get in. Is that easy enough.
it is in the town Dusty Gulch
you have to go thru the sub
you get in the wishing well in the town you can see shimmer
He is in the town named Rock Ridge.
You can't really except if you keep making the kitty on 24 carrot island follow you.
Some islands have their own names for Main Street, but town square probably refers to the Village on Early Poptropica or the places you first encounter on Astro Knights Island.
there is no lapso island on poptropica