Victor is a Cuban narrow guage engine.
Season 1 - Paxton Helps Out (cameo), Rusty and Victor, and Thomas and the Kitten
Season 2 - Yellow Rheneas, Den and the Firefighter (mentioned), Flora's New Coach, and Duncan and Smudger (does not speak)
Season 3 - Duncan's Donuts (mentioned), Henry and Stanley (cameo), and Red Paint
Season 4 - Hiro's New Snowplough, Henry and the Coal (cameo), The Country Show, Bill and the Pit (mentioned)
Season 5 - James' Bee, Different Languages! (cameo) and The Magic Engine
Victor in a likely Upcoming Episode