When Penis Breath is sitting on his egg, he says "nature's rule, not mine". This is the line Miyagi says to Daniel-San in The Karate Kid (1984), when discussing the crane kick on the beach.
When Hawk and Demetri are stretching with Miguel, talking about Sam being back, Demetri says "I thought they were platonic". Hawk replies "She does, he doesn't ". This is a reference to The Karate Kid (1984), when the Cobra Kais are talking with Johnny about him and Ali being together.
When talking in the prison and Daniel offers to hire a lawyer to help him, Kreese tells Daniel "But I want a top guy. Not one of your greasy cousins!" This is a reference to My Cousin Vinny, in which Joe Pesci plays Vinny, cousin of William Gambini, played by Ralph Macchio who also plays Daniel.