Thomson originally met founding Slipknot members Anders Colsefni, Donnie Steele and Paul Gray through their mutual involvement in death metal band Body Pit, later joined in early 1996.

Thomson grew up having a "fascination with death metal bands", including Internal Bleeding and Morbid Angel, although he has also named the Beatles as one of his major musical influences.

[3] He began his career playing guitar in a number of local bands in his hometown of Des Moines, Iowa, most notably death metal outfit Body Pit, formed in 1993.

[4] Upon joining the band, Thomson wore a hockey mask which he bought from a store, compared by author Joel McIver to that worn by Hannibal Lecter in the film The Silence of the Lambs.

[10] Thomson is also featured in the music video for "No Pity on the Ants" by thrash metal band Lupara, directed by Frankie Nasso and released in 2007.

[12] Thomson is known for playing Ibanez MTM guitars both in the studio and on tour, all of which are handmade by the company's artist shop luthier Tak Hosono.

[16] Speaking about joining the company, Thomson proclaimed that he was "immensely proud to be a part of the Jackson family", praising his custom Double Rhoads and Soloist models as "incredible".

[16] Thomson currently has three signature Jackson soloists, a limited edition USA, a standard USA, and an import, all featuring a reverse headstock, mahogany body, neck through graphite reinforced maple neck, locking nut, single volume and three position blade switch, and his signature Seymour Duncan EMTY Blackout pickups.

[19] In an interview with Jon Wiederhorn for Revolver magazine about the making of Iowa, the guitarist explained that "On days off, you'd never see me out of my hotel room ...

It was reported by The Des Moines Register that both men were drunk at the time, and that the Slipknot guitarist suffered "serious but not life-threatening" injuries after being stabbed in the back of the head.

[25] Mick and Andrew were both hospitalised after the fight, but Slipknot vocalist Corey Taylor tweeted on the day of the incident to assure fans that Thomson would recover.