Minecraft wiki entry for Easter_eggs, associated text: On October 31, zombies, zombie villagers, husks, drowned, skeletons, strays, zombified piglins, and wither skeletons may sometimes wear carved pumpkins or jack o'lanterns on their heads. These mobs would drop these blocks if killed using a tool enchanted with Looting. This feature was added in Java Edition 1.4.2 for Halloween 2012 and every Halloween thereafter.