A primeira referência verbal às Sombras ocorre no episódio da 1ª Temporada "Sinais e Portentos" , quando Londo e Lord Kiro (um nobre Centauri) debate a visão de Lady Lahira sobre a destruição da Babilônia 5:
LONDO: Then you don't believe her vision?
LORD KIRO: She's been wrong before. On my first birthday, she said that I would someday be killed by "shadows".
LONDO: Shadows?
LORD KIRO: Doesn't exactly make sense, does it?
No final do episódio,
Lord Kiro is killed by the Shadows. This is, in fact, the appearance of the Shadow ship that you refer to. It materializes briefly and destroys the raider ship that Lord Kiro is on.