He is an American actor, best known for being the lead in both seasons of Power Rangers Dino Charge and Dino Super Charge as Tyler Navarro, The Red Ranger, and series regular in SnapChat's original show, The Dead Girl's Detective Agency. Brennan appears in the film, "Corrective Measures," starring alongside Bruce Willis and Michael Rooker. He also recurred on the series, The Secret Life Of The American Teenager, and in Power Rangers Beast Morphers on Nickelodeon. Brennan has guest starred in the season one finale of American Horror Story Murder House, Disney's Kickin' It, and the CW's Supergirl. Brennan also appeared in the pilot episode of Nickelodeon's iCarly, CSI Miami, 90210, Life in Pieces, and co-starred in Gregg Araki's film, Kaboom. He has worked stunts on a variety of shows such as NCIS, NCIS LA, The Goldbergs, Jane The Virgin, Penny Dreadful **** of Angels, Seal Team, Westworld, and John Stamos' new show Big Shot, on Disney Plus. He is also an accomplished acrobat, and holds a degree in Kinesiology with several advanced training certifications.