Hamstar
A variation of the word "hamster" used simply to make the word sound different for the sake of being different or annoying. It can also be used simply to bother someone who insists of proper pronounciations or believes it has some other meaning that you are not telling them about.
Boy: "Oh... yup... hamstar..."
Girl: "STOP SAYING THAT! WHAT DOES THAT EVEN MEAN!"
Girl: "STOP SAYING THAT! WHAT DOES THAT EVEN MEAN!"