Grimlock (Transformers Cinematic Universe)

Grimlock is the supporting character of Transformers Age of Extinction and it's sequel Transformers: The Last Knight. He is the leader of the Dinobots who transforms into a mechnanical T-Rex and is part of the Legendnary Knights.

How To Ride Your Dinobot Cartoon
Grimlock found himself being the guinea pig for Optimus' Dinobot-riding lessons. To his irritation, Optimus rudely beckoned him to move forward, and was thus thrown into a barn. Optimus' mood did not improve much, but Grimlock's did, as it was now time for him to ride Optimus. The Autobot leader proved a much more compliant steed, to Grimlock's joy.

Age of Extinction
Grimlock was a prisoner aboard Lockdown's ship until the Autobots detached that section and flew it to China, though Optimus did not inform his troops of their presence. When Galvatron's new Decepticons shot down their ship, Optimus went to recruit the Dinobots for their aid. Optimus was nevertheless amazed that the "legend" existed, and freed Grimlock and his men. Optimus explained to Grimlock that the Creators intended to wipe them all out, and urged them to stand with him, or refuse and die. Grimlock immediately challenged Optimus, but despite his immense size and strength, was bested in combat. Grimlock submitted to Optimus' lead, and allowed the Autobot leader to mount him. Grimlock and Optimus led the Dinobot-Autobot charge into Hong Kong, where Grimlock killed many Decepticons with ease. Grimlock later helped escort the Seed to a safe location, but Lockdown arrived and turned his tractor beam on them. Grimlock and the Dinobots would've been captured once again had Optimus not destroyed the tractor beam with a well-placed shot. Optimus ordered Grimlock and the others to flee while he fought Lockdown. The group subsequently held the line on a nearby bridge until Optimus, Bumblebee, and their human allies triumphed and killed Lockdown. Optimus granted Grimlock and the Dinobots their freedom, and Grimlock happily departed with his team for parts unknown.

Trivia

 * In the cartoons and comics, Grimlock always speaks.