Co-founder of Michael & Harrison's Horror Movies (MHHM), Harrison Dallman's first role was in The Beast (2017). From that point on, he was a part of all of the MHHM films, the only one to act in every single one. His most famous roles are Joshua Hall throughout each Faceless film and the more recent installments in The Beast franchise, The Magician, the antagonist of the Super Smash Brothers (2018-19) series, and the villain in Son of Beast (2024), Beast: The Omen (2025), and the upcoming Faceless: Retribution (2026). He co-directed most MHHM films with Michael Decker, but he took the lead as solo director for both Beast: The Omen (2025) and Faceless: Retribution (2026). He was awarded Best Actor in a Supporting Role at the 2025 MHHM awards for his portrayal of The Magician.