Transfer

Transfer is a gray wolf, hired to sabotage Fog's journey by his rival, Mr. Sullivan. Throughout the series, he employs a variety of tactics to delay Fog and his party, ranging from leading them in the wrong direction to deliberately causing accidents. He is a master of disguise and can imitate perfectly the voices and mannerisms of those he is impersonating – but the audience can always identify him by light briefly catching his glass eye.

(Source: Wikipedia)