Magic & Mayhem for Heretic
From DoomWiki.org
Magic & Mayhem for Heretic is a commercial compilation for Heretic, created by Laser Magic and published in 1995. It contains over 1500 levels, according to the front cover of the box. It contains 997 WAD files in total. A great majority of the compiled levels were originally for Doom and Doom 2, now converted levels for Heretic with just minor changes, such as textures and monsters being replaced for their Heretic equivalents.
It utilizes DOOM-IT as a frontend launcher, which allows the installation and selection of new levels, with their respective info showcased to the user.