Merle is around six feet, broad shouldered, muscled, well built and has white hair with streaks of gray, a gray mustache and a tiny Vandyke beard. An old ragged scar bisects his chest and stomach, curving in a vicious half-moon.
When Chimera wanted to force one of the weaker leopards into animal form for a prolonged time, he offered Merle the choice of taking the weaker leopard place. Afraid that he might not recover Merle refused. Micah volunteered and returned with his eyes frozen as a leopard's. Merle stepped down as leader of the clan and gave the leadership of his pard to Micah, becoming his bodyguard and enforcer.
Merle comes to St. Louis along with Micah and the rest of the Maneaters Clan in Narcissus in Chains. After they were freed from Chimera, it was Merle who punished Noah and Caleb for their behavior towards the female pard members.
In Bullet, we find out that Merle has stepped down as an enforcer and returned to his job as a Harley mechanic. Anita notes that "he’s a lot happier being able to go back to a regular job than just be muscle to the new Nimir-Raj ".