Quizzical means:
* Expressing or feeling mild or amused puzzlement. It implies a questioning or curious look or expression.
For example:
"She gave him a quizzical look, as if she couldn't believe what he had just said."
It's possible there might be a specific context where "guizzical" is used as a slang term or a word within a particular community or subculture. However, in standard English, "quizzical" is the correct spelling.