Phoenix Logs/Banished Units/Heavy Grunts
From Halopedia, the Halo wiki
They eat Spartans for breakfast!
Heavy Grunts are elite infantry who replace Jump Pack Brutes. Heavy Grunts are Yapyap THE DESTROYER'S enforcers , wearing heavy armor and armed with plasma pistols. When they need to break out the big guns the leader uses his Fuel Rod Cannon. This cannon can be upgraded with the party's Over special ability, which fires an EMP round that stuns vehicles and aircraft. And though war never changes, their unit size can. The My Plus One upgrade adds an additional squad member to the entourage.
Heavily augmented using strange machinery found on the Ark, Heavy Grunts are part Grunt, part machine, all awesome. Even without their new battle armor the Heavy Grunts are bad to the bone, and their chainmail undervests, mirrorshade lenses, and bad attitude prove it. They are led by the Shadow Master of Buwan, a red—beret—wearing Grunt spoken of in hushed whispers, who has taught his disciples ancient Balaho martial arts and a number of useful rope knot tricks.