The Cave's Voice, Scary Cave by Tuffy, is a very creepy voice and the main antagonist featured in the 1991 cartoon film, The Little Engine That Could and the secondary antagonist in Tom and Jerry & The Little Engine That Could. It was advertised as the main antagonist like the original film, but this was the plot to be outranked by the new main antagonist.
It was a cave resembling a demonic face with extremely glowing red eyes, claws and is only heard saying "Too little. Too little.", before starting to drop icicles and collapsing in an avalanche as the train narrowly escapes. In the Tom and Jerry version of the film, an avalanche caused by the Ghost Train.
The Cave's Voice appeared in Sailor Moon Crystal: Adventures in FernGully. It's had the same role as the movie.