Bear, formely known by his number, D7101, is a friendly green diesel.
Bear came to Sodor on trial with an associate of his, D199. At the time, Bear had no name, only a number: Diesel 7101. However, when Diesel 199 was rude, Bear put him in his place and tried to be respectful to the engines of the North Western Railway. Later, Henry rescued both Bear and Diesel 199 from some technical malfunctions from both parties. Bear learned a great deal from this experience, seeing steam engines as hard-working, resilient, utterly inspirational. Henry put in a good word for Bear, and he joined the railway. The name "Bear" had stuck, due to the loud growls his engine made.