Thrugann was a female otter and sister of Thrugg. She helped Brother Hollyberry gather herbs for his medicines. She and Thrugg had a competition to see who could eat more shrimp and hotroot soup. Thrugann was the last Redwaller to get Dryditch Fever, but Dumble and the Wild King MacPhearsome arrived with the Flowers of Icetor just in time.
- In some printings of Salamandastron, Thrugann's name was occasionally spelled as Thrugan (with only one 'n'). This was probably a typographical error in the editing process.