June Lockhart is making the looooong stretch from "Lassie" to "Ren & Stimpy."

Lockhart - who played one of TV's best coiffed, most understanding mothers ever on "Lassie" from 1958 to 1964 - just finished voicing an episode of Nickelodeon's hip and often gross cartoon."I don't do anything horrible," Lockhart says in the Aug. 13 issue of TV Guide. "But it's one of the most disgusting episodes ever, and it's sure to increase my prestige with my grandchildren more than anything I've ever done."