The Buzzlegum Keeper's Hat is a hat accessory you can purchase at Miss Petula's Paper Pets in Viva Piñata and Viva Piñata: Trouble in Paradise. In Viva Piñata: Pocket Paradise, it is instead purchased at Gretchen Fetchem's from the accessories category.
This accessory will make any Buzzlegums that are wearing it automatically produce Honey at a Honey Hive without requiring you to feed them a sunflower (TiP) or a buttercup flower (Classic & Pocket Paradise).