From publisher blurb:
Mutants of the Multiverse is a guide to mutants in the Transdimensional Adventures RPG, including new mutant subspecies hailing from distant dimensions or created by dimensional travel itself. The mutant race rules from the Core Book are built on to create various creatures, whether truly mutated, genetically engineered, or joined with mutated or alien organisms; hailing from a variety of worlds - futuristic, fantastic, post-apocalyptic, or merely alien.
Includes over 40 new mutant subspecies, all potentially useable as PCs.
Adapted - genetically engineered for new environments: Jovian Brain, Loper, Moon Orc, Quasiplanar, Red Dune Runner, Seraph, Spacer, Spark, UMEC Warrior.
Exotic - alien in origin: Darkling, Jumper, Nevian, Purgatory Exotic, Tentacle Ape.
Halfmen - monstrous creatures 'uplifted' with human DNA - Arroyo Devil, Gedren, Green Man, Slugman.
Magic-born - native to fantasy realms - Alchemuted, Artefact Wielder, Teleport Error, Thrice-Accursed.
Monstrous Mutants - born of radiation on post-apocalyptic worlds: Augmenter, Brute, Formless, Havenborn, Weirdie; and multimutants based on these.
Symbiotes - pairing humans with mutated or alien organisms - Archean Host, Demon Graft, Legionary, Restorex.
Superhumans - 'enhanced' humans with improved strength and abilities - Altered Champion, Elite, Parahuman, Starblooded.
Transdimensional - changed by dimensional travel or otherworldly effects - Displaced, D-Marauder, Elsespawn, Netheric, Shifted, Singularity, Visited.
MotM also includes a number of new mutations, as well as an index of previously published mutations and expanded random generation tables.
This is a system-heavy book which is primarily intended for use with the core Transdimensional rules. Some but not all mutant varieties are usable with the free Apocalypse Essentials post-apocalyptic rules.