User blog comment:Narfcwing/What is the chance of the gun being dropped in the minecraft Easter egg?/@comment-5686539-20130312171401/@comment-5686539-20130312180118

You might be able to leave the area (Caustic Caverns) alone after that for ~half an hour or more for the area to reset; but that might not reset the Minecraft area. When I farm for Vermivorous in CC and leave the area for Tundra Express, it only takes about 10 minutes for CC to reset, but the easter egg area doesn't. So, if you really want the Blockhead/Longbow faster, it is much more time-efficient to just save and quit; but back to your question of whether one could just leave CC and re-enter... No. That only works for raid bosses. The only enemies that are truly considered raid bosses - whether Seraph Guardians or not - are the Bunker, Terramorphous, Hyperius, Master Gee, Pete, Voracidous and Dexiduous. All other enemies are either unique or bosses. I hope this has clarified your problem.