|Portrayed by:||Jeremy Sisto|
|First appearance:|| "Pilot" (uncredited)|
"An Open Book" (psychical)
|Last appearance:||"Everyone's Waiting"|
|Relatives:|| Bernard Chenowith (father)|
Margaret Chenowith (mother)
Brenda Chenowith (sister)
Nate Fisher (first brother-in-law)
David Fisher (brother-in-law)
Claire Fisher (sister-in-law)
Willa Fisher Chenowith (niece)
Maya Fisher (adoptive niece)
Daniel Nathanson (second brother-in-law)
Forrest Nathanson (nephew)
|Significant Other/s:||Claire Fisher (ex-girlfriend/sister-in-law)|
He and Brenda had a close relationship as children but he was later diagnosed with bipolar disorder and hospitalized. When released, he showed up at her house unannounced and later attacked her, attempting to give her a tattoo in honor of a book character they both liked as children.
He was previously in a relationship with Olivier Castro-Staal, who taught him art at college. He meets Claire Fisher in 2001 and the two later become an item but he ceases taking his medication, thus becoming more unstable, which leads to Claire breaking up with him for her own safety. He pleads with her to take him back but she refuses, even though he goes back on his medication.
When Brenda dies, he is shown by her side talking to the doctor.