Armenel is Great Eagle of the Misty Mountains. He can be considered an elderly Eagle, as he fought at the Battle of the Five Armies. It is also good to note he carried a dwarf to safety. He is quick tempered and hot blooded, and eager to get revenge even after the death of Bargrisar. He is a hardy warrior, and does not questions his orders.

Armenel was part of the Eagle force sent to the Ettenmoors in search of Bargrisar, the stone-giant, to end his wrath. He, along with Gwaihir, his lord, and Baranthor, flew up to the Ettenmoors just as Bargrisar was being slain by the Fellowship of the North (Eradan, Andriel and Farin) and Beleram. After Gwaihir gave leave to Beleram to accompany the Fellowship of the North on their hunt for Agandaur, Baranthor quickly asked to also accompany them, eager to prove himself a worthy Eagle. Armenel, not wanting to be left out of such a memerable quest, also asked to join the new forming Fellowship of the North. Gwaihir gave leave to them both, and the Fellowship was formed with "three who cleaved the air" and "three who walk the ground".

Armenel, Baranthor and Beleram carried the Fellowship of the North to Rivendell to inform Lord Elrond everything they have learned. Elrond then sent them to Mount Gundabad to scout for Agandaur. When they arrived, they found Fell Beasts patrolling the outskirts of the mountain. So, Beleram commanded that himself, Armenel and Baranthor distract them. Armenel and the other two Eagles also came to the Fellowship's aid when the mountain roof started to come down on top of them. At Bruni and Nordri's (the dwarves found at Gundabad) command, they travelled many leagues through the Grey Mountains at to the secret stronghold of Nordinbad. From there, to Mirkwood, to find Radagast to see if he knew the wearabouts of the dragon Urgost. They then carried the Fellowship to the dragon's lair. But after they learned that Nordinbad was under siege, they rushed to it's aid. Beleram instructed that they should destroy the siege machines while the Fellowship held the gate. They dive-bombed the siege machines, but swooped back into the air to wind up for an attack on the trolls beginning to assault the gate. But as they soared in, a missle launched by a nearby siege machine sundennly appeared, and exploded, instantly killing Armenel and Baranthor, and knocked Beleram from the sky. Sadly, Armenel died at the siege of Nordinbad.