The Timmyton's jaws and tail are motorized by the same EV3 medium motor, which is plugged into port A. The medium motor is situated between the two drive motors.
A special gearbox splits the medium motor's power so it can simultaneously power the jaws in the front and the tail in the rear. A bevel gear directly attached to the medium motor's output meshes with two gear trains; it meshes with another bevel gear through a 90-degree connection to transfer power to the jaws, as well as a set of gears located above it, which transfer power to the tail.
Bevel gears are a special type of gear; they have a conventional circular shape like spur gears, but the corners of their teeth are cut at an angle. This allows them to form 90-degree connections with one another while still being able to form conventional parallel gear meshes like spur gears can. The Timmyton takes advantage of the bevel gear's ability to form both types of connections; this is how the Timmyton splits the power from one motor within a compact footprint.
The gearbox is visible on the underside of the robot near the mouth:
