"Lassie was an unusual series in that the canine star did its own acting, with owner-trainer Rudd Weatherwax giving cues and providing on-air narration. The original Lassie (a male named Pal) took "about 15 whining and barking cues a week. He also pants with exquisite nuance, but cannot be depended upon to growl or snarl on cue" (Time) Animal imitator Earl Keen was thus on hand to fill in where Lassie failed to speak, and to play the roles of other dogs."