Proteus

Proteus is a small bright yellow Narrow Gauge tank engine. He is a very special engine with a magic lamp hung upon his funnel. Legend has it if someone finds the lamp, their wishes are granted. Skarloey tells this story to the other Skarloey Railway engines, which then led to Peter Sam going up and down the line looking for the magic lamp.

Proteus was only featured in one Season 9 story, The Magic Lamp. He appears to have the same body as Sir Handel, which many believe is what led to the later's return in the show's 10th series.

His clues to find his magic lamp are feeling a rush of wind when the lamp is near, hearing a strange creaking sound, and see a flickering light that shines on and off, off and on.