Lesser Bunnies (from eggs) have a small chance at dropping bluesparkle loot bags. I've gotten a few outfit pieces from them. I'm talking about the HUGE bunnies. They drop a proper loot chest but sometimes there is loot display and no loot roll for the items. It may have to do with party members being invited AFTER the bunny is tagged. I believe that a member of the party who was invited AFTER the bunny was tagged opened the chest, saw the loot preview, chose Loot All and the items ALL went into his inventory without the loot displaying for all party members. He then logged off with his bounty.
Hope the Cow is looking into this and resolves the issue. I WILL NOT be inviting players to party after a mob is tagged from now on. Which is a shame because I invited the person to group because he was helping with DPS and that deserved a chance at loot.