Thorax is a male changeling. He becomes the new leader of the changelings following the defeat of Queen Chrysalis. He is referred to as King Thorax in other places. Thorax has somewhat more whole ears and tail, slightly differently-colored eyes, and differently-colored back armor. Following his metamorphosis, Thorax is much taller and has a different color scheme—and beetle-like mandibles protruding from his forehead. Thorax, unlike most of his kind, is demonstrably amiable and considerate with a sincere yearning for friendship. However, prior to meeting others, he bears much doubt that anyone could ever want to be friends with a changeling. When offered kindness or surrounded by love, Thorax occasionally reverts to his basic impulses and hisses threateningly at others. He is very bug-like but overall friendly, and bold and courageous when he has to be, like when he is confronted with a foe, or someone threatening him. Thorax is shown to panic when a situation turns dire, even to the point of hyperventilation, though he sticks with the rest of whatever team is with him despite his fears. He looks to others wiser in friendship for leadership, and he demonstrates selflessness. Thorax is shown to be excitable and curious, but at the same time, he struggles with the weight of his new leadership role, admitting to Spike that he has trouble asserting his authority. Thorax shows a strong sense of loyalty towards his brother, Pharynx, stemming from Pharynx always defending him from bullies when they were young. He is steadfast in his belief that there is good in Pharynx, refusing to banish him from the hive for his behavior, and pointing out to Pharynx that he still cares about the hive despite all the changes. Thorax seems to share the displeasure of the other leaders and joins them in advancing on the unicorn, though Princess Celestia convinces them not to become violent. Thorax lives in an unfinished hive with other changelings, and often makes various noises akin to what a bug would make. he is welcoming to everyone, and strives to be better at his leadership. Thorax has bug-like anatomy, including his genitalia. He leads a hive that is constantly changing and morphing—only being able to be navigated by other changelings, hence why it is a changeling hive.