He was voiced by Will Friedle also voices Ron Stoppable.
He has bright red hair and black eyes. His hair is worn in a mohawk with shaved sides and is very messy.
He is a cocky and smartmouthed individual. Commonly referred to by his brother-in-law (Doc Saturday) as a huge child, he possesses a loud "in your face" attitude similar to his sister's, and can be somewhat of a bad influence on Zak due to his methods and morals. Doyle can be funny and light-hearted and has a 'come what may' outlook on life. For the right price, he's willing to help his family. He is a kind person, but his orphanhood lifestyle lead him to put people on the edge of his heart, rarely becoming emotionally invested in others until he reunited with his sister approximately 25 days after they were separated.
Doyle was born to a family of adventurer-scientists. After his family was scattered during a severe blizzard in the Himalaya.
Years later, he was reunited with his long lost brother, Drew.
In 'And Your Enemies Closer', he and Drew (who's search for Argost's past lead him there) reunited in Himalaya at the same place that their family was lost. He then learns that it wasn't the blizzard that separated him and Drew, but an attack on their camp by The Yeti. Much to his shock, he and Drew discovered that the cryptid that destroyed their family is in fact Argost.
- Coincidentally, his voice actor, Will Friedle, and Nicole Sullivan (voice of Drew Saturday) both voice Ron Stoppable and Shego from Disney's Kim Possible.