This was an issue with my mom's high school - they were the Indians but were later renamed something like Warriors. It got the point of the mascot across without offending any races by singling them out as a novelty stereotype. While "redskin" isn't the most offensive ethnic slur out there, it is a bit of an odd choice when you really think about it. i.e:
"What's your team mascot?"
"The Boston Black People"
"o_O"