- The same animal can't be repeated twice.
- This includes using variations such as "rattlesnake" when "snake" has already been given as a response.
- If there are several different names for or breeds of the same species, go ahead and use them, so long as it doesn't violate the rule above.
- No using binomial nomenclature (that Pan troglodytes is a chimp, you turkey).
- There are probably more rules we can think of, but just use common sense and keep the game fun.
I'll start off with: Marmot