The Simpsons

The longtime “Weekend Update” co-anchor will voice a version of himself “who has written an idiotic children’s book,” Simpsons showrunner Matt Selman tells TVInsider. The episode airs Sunday night.

“I’m finally back on The Simpsons this Sunday with a mind-blowing episode that has been 36 years in the making,” O’Brien teased earlier today. “I can’t imagine a bigger national event in the next five weeks,” he added.