Behold, Eck! - S2-E3
Plot hole: Eck gives Dr. Stone one of his eyes so the scientist can create a lens to improve the alien's vision. At the end, Stone hands Eck the lens, but not the eye. When Eck puts on the lens, his missing eye reappears out of nowhere. (00:48:30)
Behold, Eck! - S2-E3
Continuity mistake: When Dr. Stone's assistant helps him up from the floor, there's a lopsided, circular diagram drawn on the chalkboard behind them. One shot later, the diagram has changed into a perfectly round circle and has moved itself several inches higher on the board. (00:06:10)
Andro: Better to die than to sit and watch the world die.
The Forms of Things Unknown - S1-E32
Trivia: Part of Dominic Frontiere's haunting musical score for this episode later became the theme and background music for the TV series The Invaders, a show for which Frontiere served as the primary composer.