As IMDb notes, Boris is portrayed by the multi-talented Jemaine Clement, who hails from Masterton, New Zealand, and has had a hugely successful career as a comedian, musician, and actor. Clement got his start in entertainment by forming a couple of comedy troupes with none other than director Taika Waititi: So You're a Man, and The Humourbeasts.
However, it was his collaboration with Bret McKenzie as the comedy duo/band Flight of the Conchords that shot Clement to fame, as the pair of lyrical comedians toured the world and even produced a well-loved television show, for which Clement earned an Emmy nomination.
In 2020, Clement spoke with The Phoenix Foundation about how the pair's comedic songwriting process evolved over time. He said, "I guess there's two ways we write songs — maybe three. One is from real experience; two, is like any other song, just imagining characters or a story. And third is just to make fun of other songs, and I think we were doing that more. We had a song on the album called 'Demon Woman,' which was just making fun of 'Devil Woman' and all these ridiculous kinds of songs."