A son of Echion and Agave, the daughter of Cadmus. (Eurip. Phoen. iv. 942; Paus. ix. 5. § 2.) He was the successor of Cadmus as king of Thebes, and being opposed to the introduction of the worship of Dionysus in his kingdom, he was torn to pieces by his own mother and two other Mainades, Ino and Autonoe, who in their Bacchic frenzy believed him to be a wild beast, (Ov. Met. iii. 513, &c.; Eurip. Bacch. 1215; Philost. Imag. i. 1; Apollod. iii. 5. § 2 ; Hygin. Fab. 184; Serv. ad Aen. iv. 469; Nonnus, Dionys. xlv. 46; Oppian, Cyneg. iv. 289.) The place where Pentheus suffered death, is said to have been Mount Cithaeron, but according to some it was Mount Parnassus. Pentheus is said to have got upon a tree, for the purpose of witnessing in secret the revelry of the Bacchic women, but on being discovered by then, he was torn to pieces. (Eurip. Bacch. 816, 954, 1061, &c.; Theocrit. xxvi. 10.) According to a Corinthian tradition, the women were afterwards commanded by an oracle to find out that tree, and to worship it like the god Dionysus himself; and out of the tree two carved images of the god were made accordingly. (Paus. ii. 2. § 6.)