In retrospect,
Opiate seems a little haphazard, but it's possible to hear the seeds of
Tool's oppressively bleak, cerebral metal in such cuts as "Sweat" and "Opiate." The two live tracks, "Cold and Ugly" and "Jerk-Off," don't sound out of place, since they share the same churning riffs, black noise, and doom that characterize
Tool's sound. This is not as developed as either
Undertow or
Ænima, but it's possible to hear the roots of those albums all over this EP. ~ Stephen Thomas Erlewine, All Music Guide