Consider this is a crossover between “Before They Were Stars” and my upcoming column about Mystery Science Theater 3000. Clint Eastwood’s first acting role ever was a 30-second bit as a lab technician in Revenge of the Creature, a lousy sequel to Creature from the Black Lagoon which was riffed on MST3K. Remember: even someone who’s built up one of the greatest film careers of all time had to start at the very bottom.