TModloader, Linux, and Collector’s Edition

Terraria has a bonus bunny pet if you buy the Collector’s Edition. Whether or not you have Collector’s Edition, every version of the game still needs to have the data for the bunny pet for multiplayer. The way the game determines if you own the Collector’s Edition is through a registry key, fittingly titled “Bunny”. Setting this registry key on a normal Steam copy of the game will, therefore, also give you access to the bunny pet. While the Collector’s Edition did not officially release for Linux, you can still create and set the registry key, since Mono provides a registry key simulator for non-Windows platforms which reads from an XML file in a certain directory.
TModloader does not use Mono, and instead runs on modern .NET. Modern .NET does not provide a registry key emulator for non-Windows platforms. Instead of writing some code to check for the file used by the vanilla game, they disabled the ability for non-Windows versions of TModloader to obtain the bunny pet, even if you bought the Collector’s Edition.

The value in the game’s code that dictates whether the bunny is enabled or not is a public static boolean field called runningCollectorsEdition, located in the Main class. Do with this what you will.