Jamjars is Bottles' brother and serves as the replacement trainer for Banjo and Kazooie in Banjo-Tooie. Assertive and strict, this militaristic drill sergeant mole requires the pair to prove themselves by collecting a certain number of musical notes before teaching them any new moves. Like his brother, Jamjars doesn't think too kindly of Banjo's smart-aleck sidekick, Kazooie, but tolerates her enough to teach the pair some of the game's most important moves, possibly because of Kazooie's enthusiasm to beat the living (or in this case, undead) daylight out of Grunty.
Banjo and Kazooie must find his hatches in each world (unlike Banjo-Kazooie, all the worlds in Banjo-Tooie have at least one hatch and one move to learn) and have the correct number of notes to obtain the next move. His hatches are flat with a red light if the move hasn't been learned yet and green when it has. Pressing B button (N64) next to a green-lighted hatch will give a quick recap on how the move is performed. Also, if Banjo opens a hatch without full health, Jamjars will provide him some honeycomb "rations", instantly filling the health bar.
Each move is taught by Jamjars dancing to a military style flute and drums tune, with the instructions being sung in rhyme, similar to an Army march or cadence. When finished, he "dismisses" the duo, jumps up high, and dives back into his opened hatch. Occasionally as a gag, the hatch door will close early, causing him to land on his head. Comically, he groans, opens his hatch just far enough to wiggle inside, and then opens it once again to grab his fallen hat.
Banjo-Kazooie: Nuts & Bolts
In Banjo-Kazooie: Nuts & Bolts, it is revealed that Jamjars has now become the MC of Spiral Mountain's local radio station. He tells the heroes that it has been ten years since they were created (Banjo-Kazooie had been released 10 years prior) and tells them how fat and lazy they've become since Banjo-Tooie.