Long Protein Strings (File:Proteinstrand.png) were the third prize currency from the Treehouse of Horror XXV Event. For each Rigellian tapped, players earned 5 Long Protein Strings. Players could also earn Long Protein Strings from visiting neighbors, earning 1 Long Protein String for the first 90 actions per day. If the Rigellian Hunting License was bought by the player, they could've earned more Long Protein Strings from squishing Rigellians.