Dead fish used to be a staple at Lynah Rink when Cornell hosted Harvard.
 
They'd be tossed prior to the opening face-off (frequently during the Anthems--
sidebar question -- Do any schools besides Cornell play both the Canadian and
American National Anthems?) with smaller  assaults before the 2nd and 3rd
periods.
 
In addition, a live (most years) chicken would be leashed to the Harvard
goal just prior to the Crimson's arrival on ice for the third period.
 
Several years of frisking fans enterring the rink reduced the quantity of
seafood, but even though I missed the last few years, I bet the chicken
still makes the annual appearance.