In July of 2005, he joined Henson's puppet improv troupe and has performed on stage in Puppet Up! - Uncensored and Stuffed and Unstrung. Johnson assisted Julianne Buescher in puppeteering Louisa Cappellini in the unaired pilots for Late Night Buffet with Augie and Del. He also assisted Bill Barretta in puppeteering Bobby Vegan in a special Henson Company lot welcome video for Adventures By Disney. In 2007 Sean and his twin brother Patrick were taped by Brian Henson to teach weekly puppet technique classes at the Henson lot for Stuffed. In 2011 Johnson performed onstage at the 53rd Annual Grammy Awards with Cee Lo Green, and many fellow Henson puppeteers. Johnson's puppetry can also been seen in a few episodes of the Henson Alternative web series, Alt/Reality.
Johnson built a handful of puppets for Stuffed and Unstrung including the popular Red Crab used in the "job interview" sketch. He also helped build various puppets for the Creature Shop including two Buddy the Dinosaur walk-arounds, a giant monster for Kanye West's Glow in the Dark Tour, Rico a lovable but accidentally foul-mouthed mammal for Air New Zealand, the three blind mice for a 2012 Reading is Fundamental PSA, and more.
Sean Johnson began building puppets and performing puppet shows professionally after joining the San Francisco Puppeteers Guild in 1993.
Outside of the Jim Henson Company, Johnson is co-owner of Swazzle a Glendale based puppet company.
His puppeteer credits include: "The Muppets", "The Pee-wee Herman Show", "The Simpsons - The Fight Before Christmas", "Team Smithereen", "Forgetting Sarah Marshall," Jib Jab's "So Long to Ya 2010", "Einstein Pals," "Playing with Dolls," and "Baby Monet."