Everything I've read from people who knew him say that the dimwit character he played on the Monkees TV show was completely unlike his real self; he had developed the persona while playing in folk clubs.
Peter was actually well-educated and intelligent. He was certainly a talented musician, playing guitar, bass, keyboards and banjo in the Monkees. He also wrote the song "For Pete's Sake" which was used as the music for the closing credits of the show's second season, and other songs the Monkees recorded.
After leaving the Monkees, he formed a band called Peter Tork and/or Release, used up and gave away the money he'd earned as one of the Monkees, and spent a few months in prison for possession of hashish. After that, he spent a few years as a high school teacher at a private California high school, before the Monkees reunions sparked by MTV showing the series in the mid-1980s. In between reunions, he performed solo music and in bands such as Shoe Suede Blues.
He died on February 19, 2019, six days after his 77th birthday. The cause of death was adenoid cystic carcinoma, a rare cancer which affected his tongue and salivary glands, with which he had first been diagnosed in 2009.
Source:
http://www.petertork.com
http://voices.washingtonpost.com/checkup/2009/07/my_blog_last_week_about.html
https://uniqueguitar.blogspot.com/2019/02/peter-tork-his-life-and-his-instruments.html