Jim, as stated by Tim Lockwood, is the "Bad Boy" of the Lockwood family. This, at first, may make it seem like he would be up to no good and harmful to others, but he really isn't very bad a guy. Even when he tried to replace Tim Lockwood, he just claimed that apparently, Jim is always up to tricks like this and appears to be completely fine with the incident, claiming it also gave him a good fishing opportunity. Otherwise, Jim looks and sounds fairly similar to Tim Lockwood. The biggest difference other than the way they dress is that Jim lacks a full uni-brow.
- Jim lives a very adventurous life, although he could secretly want a peaceful home life like his brother has.
- Jim's most common quote is "I am such a bad boy."
- Jim makes a second, brief appearance in Flint's Fabulous Future where he works for Brenda at Sardeenie's. When Flint is hired, Jim is fired on the spot for seemingly no reason.
- Jim's third and final appearance is in the episode Tim, Jim and Kim, where it is revealed that Tim would often unintentionally ruin Jim's relationships by charming the girl Jim was dating., Though this was never Tim's intent, Jim is still angry about it.