Halloween Tricks is an expansion pack by NRD2003. The expansion has over 51 animals and has been one of the most anticipated expansions of the zoo tycoon user made franchise next to Ecuatorial Holidays and Remake Ultimate Collection. The expansion was thought to have large amount of glitches, the most severe being a glitch that prevents certain staff, the cloning button, and the extinct research lab from working properly, it also causes the ingame menu to glitch, to point of being unusable, but NRD2003 and Artifex updated all the files fixing the bugs.