Lugnut is large (4 to 5 times the mass of your average data clerk) and carries an enormous mace that is itself taller than many Transformers. Unfortunately, he's the sort of dense, plodding "semi-intelligent life" (as Megatron puts it) who'll just stand by dumbly without a superior's order to act. This makes Lugnut rather easy to manipulate once he gets over the surprise of actually being talked to. Lugnut seems dimly aware of his own nature, and will generally admit to not always remembering things he's been told, even if they were orders from Megatron.
When Orion Pax came to Kaon for his first face-to-face meeting with Megatron, Lugnut and Barricade "greeted" him at the entrance to their headquarters. Orion quicky identified Lugnut as the weak-link among the two guardsmen and would likely have succeeded in talking his way past the big lug if it weren't for the more suspicious Barricade. As the war escalated, Lugnut proved himself to be worthy of Megatron's "elite" forces, and was on-board the Nemesis when they gave chase to the fleeing Ark.
Lugnut fought during the battle on Junkion, and remarked to Megatron on the locals' hardiness.
- Lugnut's appearance seems to be heavily based off of his Animated counterpart.