Grotto is a member of the Nova Posse (IDW), a part of the Nova Squadron division of the Imperial Aerwyl Starfleet in Dimension X in the IDW comics. Grotto is a large, squarely built yellow creature, often seen smoking a cigar.
The Nova Posse comes to the rescue of the of the Neutrino resistance fighters on the planet Balaraphon in Dimension X during the Posse's debut in The Armageddon Game: Opening Moves issue 1. Grotto is one of the three Posse members who leaps out of the Nova Posse's ship, the Freedom One, to rescue Kala.
Grotto is seen again in The Armageddon Game issue 2 as he and Exeen wait in the repair bay on the Blastorama Pleasuredome for Torbin Zixx, who they are trying to capture.