Zoas.
This is something that annoys me. Many people when abbreviating "until" write "till". That is an action, to turn and aerate soil so that crops may grow better. "I'm going to wait here till the movie is over" makes no sense. The major reason till is used over til is probably because spell check used to flag "til" as a misspelling, because technically as an informal contraction it was not an official word. What's the number 1 replacement? Till. Doesn't make any sense. If you're using till instead of til, you are misspelling.
Likewise, Zoos is probably a mutation of zoas that was developed because various spell check algorithms flagged zoas as not being a word. Number 1 replacement? Zoos. The problem is once you ingrain something in the heads of people, it's incredibly hard to stamp out, whether it's right or wrong.