Smallville: Rush (2003)

Synopsis
The Indian caves introduced in the previous episode "Skinwalker" happen to harbor an alien parasite which feeds on the adrenal glands of teenagers. Among those infected by the parasite is Clark Kent's (Tom Welling) best friend, Pete (Sam Jones III). His mind and personality altered by the "invader" in his system, the usually shy and mild-mannered Pete becomes a reckless, extroverted daredevil -- thus endangering not only his own life but those of everyone around him. ~ Hal Erickson, All Movie Guide