Grimlock

“All we Dinobots working and working for months now,” Grimlock said. “Boring work! Dig hole here, pound scrap there, put up girder here. Us not like it, but me Grimlock say, ‘Dinobots, do what Wheeljack say!’ And Dinobots do.”

[...]

“They did not stumble,” Cyclonus said. “Grimlock was ordered back to the evacuation twice, once by Wheeljack, once by Optimus Prime. Both times he paused briefly, considered the order, then ignored it and proceeded onward directly towards the site. The only reasonable explanation is that he recognized that the attack on the human outpost was a diversion, and from its design managed to reverse-engineer the likely location of the real operation. There are several other instances as well, but it is the most marked among them.”

[...]

“Me Grimlock still not like you, but at least you not dumb. Dinobots fight with Decepticons from now on.”

“Grimlock!” Wheeljack said, horrified, reaching out a hand.

“No! Forget it!” Grimlock said to him. “Optimus give Dinobots bad orders for last time.”

“Wait, okay, Grimlock, listen, I know this is complicated—” Wheeljack started.