Hockey Memes

Only in Canada would a physics problem involve a hockey puck colliding with a rubber octopus on ice! The problem is actually using conservation of momentum (puck momentum = combined momentum after collision), but I'm more concerned about why fans are throwing cephalopods during hockey games. Is this some bizarre Canadian ritual I missed? Next chapter: "A moose with mass 700kg collides with a maple syrup truck traveling at 25 m/s..."