One of the two main characters of Sheath and Knife. He is the younger brother of Will (Harmarist) and son of Harold (Harmarist), and is in an incestuous relationship with Will. Alex is 10 years old at the beginning of Sheath and Knife and 12 by the end, making him a child throughout. He is homeschooled by Will, and his parents are frequently absent.

Alex undergoes a significant personality shift over the course of Sheath and Knife. Though initially innocent and naive, he becomes more sexually aggressive as the series progresses until he is almost unrecognizable from his initial appearance, eventually becoming the dominant partner to a submissive Will.

Alex loves video games and is extremely good at them, often outperforming Will. He also frequently engages in casual nudity, even before entering a sexual relationship with Will.