User modification, or modding of games in the open-world sandbox Grand Theft Auto series is a popular trend in the PC gaming community. These unofficial modifications are made by altering gameplay logic and asset files within a user's game installation, and can drastically change the gameplay experience: from replacing the player's character model with a fire breathing cat, to spawning zombies throughout the map. Frequently created by anonymous 'modders', modifications are presented in the form of downloadable files or archives. Third-party software has been indispensable for building Grand Theft Auto mods, due to the lack of official editing tools from the developer, Rockstar Games. Mods for Grand Theft Auto are generally developed for use on the PC versions of the games, since the platform does not prevent modifications to installed software; however, similar content for console versions does exist to an extent.