From their product page:
Omnisphere Grotto is a collection of 120 brand new cinematic patches for Spectrasonics' Omnisphere 2.6 synthesizer. It comes with 253 new sound sources, from real instrument recordings that have been lovingly brutalized through merciless editing and weird and crazy signal processing.
The patches in Omnisphere Grotto are science experiments gone wrong, monstrous and machine-like, but in which you can still hear their organic origins and an expressiveness that competes with that of acoustic instruments. This is an aesthetic heavily inspired by the works of composers like Mica Levi, Hildur Guðnadóttir, Ben Frost and Mac Quayle. Omnisphere Grotto can really punch up and add tense grittiness to your crime, horror, thriller or dark drama scores.