Grr-Fred is the the chief security officer of the Troglodyte.
The Trials of Apollo
The Tower of Nero
He and other troglodytes surround Nico di Angelo when the son of Hades brings Apollo, Meg McCaffrey, Rachel Elizabeth Dare, and Will Solace to ask Screech-Bling for his help. When the group is presented with a skink, a rare delicacy for them, they take the five to their camp. When they eat dinner, Nico requests help in destroying Nero’s filtration system from flooding the sewers and burning New York City. When they decline their guests say they might lose sources food and hats and be fed to Python. They initially agree to help, but become uncertain when a heard of Taurus Sylvestre track the five to their encampment. He drags Meg to a nearby river and they jump in when Apollo joins them. He pulls the three out of the river and, after a brief rest, tunnels to an area near Nero’s tower and goes to leave, but Apollo stops him momentarily to give him a ball belonging to a boy the mortal god saved. He takes it and leaves.
After the troglodytes sabotage Nero’s filtration to pump Greek Fire into the sewers, he participates in the Battle of Nero's Tower where he and other trogs take on mortal security guards.
Appearance
Grr-Fred is a grown troglodyte who wears a firefighter’s hat, a police officer’s hat, and a cowboy hat.
Personality
Grr-Fred cares for the safety of his own kind and does not like humanity, feeling they are destroying the 'Crusty Crust'.