GingivitisG 10

Bites count against both you and your buddy. Both regular gingers (on the first trip through the school) and Nazi zombie gingers (second trip through the school) count for this. This is missable since these are the only two times you encounter gingers. Zombie gingers are more likely to bite you, so my suggestion is to just take whatever bites happen to come your way on your first trip, and then farm whatever is left on your second trip. Make sure to create a save before entering the basement just in case you accidentally block (since that's probably pretty reflexive at this point in the game) and knock them out, since you only get 2 chances on your second trip. If you finish both battles before being bit your third time, reload and try again.