Czech Black Metal act formed by frontman Blackosh of ROOT repute in 1996. Subsequent recruits would be bassist Igor and INNER FEAR drummer Marthus. ENTRAILS contributed their rendition of 'Jáma Pekel' to a 1999 MASTER'S HAMMER tribute album compiled by Redblack Productions. The group debuted in their own right with a 2000 split EP 'Black Vein' shared with Italian act NECROFLESH. Limited to 500 copies the EP comprised both live and studio recordings. After these sessions Marthus made way for Holloshman of DEMENTOR.

The ENTRAILS 2001 'Serpent Seed' album closed out with a trilogy of cover versions in ROOT's 'The Way Of Destruction', EXORCIST's 'Black Mass' and 'Nightdemons' originally by CRUX. ENTRAILS would also contribute their rendition of 'Jáma Pekel' to a MASTER'S HAMMER tribute album issued by Redblack Records.