Ha, this has actually happened to me. Twice!
On LBT 8, when I was younger, I used to think Tippy was female. I hadn't watched the film in a while, and a few years ago when I checked the wiki on LBT 8, I learned that Tippy was actually male... lol boy how that changed my view.
Also, when I was young, and until a few years ago, I used to think Rabbit on Winnie the Pooh was female too! I hadn't watched either films in quite a while, but I never paid those characters a second thought on their gender till actually learning about it xD
I always imagined Tippy as Spike's new and quirky female friend and Rabbit as the grumpy, funny, old female rabbit of the Hundred Acre Wood.
Have you guys ever had misconceptions about characters and their gender

?