Complex sentence: He frequently provided the voices of numerous alien creatures on "The Outer Limits"--including the episode "The Guests"--for which he was uncredited, and may have been involved in English-language dubbing on lesser-known spaghetti westerns.
Split into simpler sentences: He frequently provided the voices of numerous alien creatures on "The Outer Limits"--including the episode "The Guests"--for which he was uncredited. He may have been involved in English-language dubbing on lesser-known spaghetti westerns.