They said they were going to deliver some big names - and they have!

Seth Rogen is the first celeb to be apart of the 21st season of The Simpsons.

The funnyman can "die a happy man now" after co-writing and lending his voice to the animated series.

Seeing as Seth is able to write a HIGH-larious scripts like Superbad and Pineapple Express, writing for the long-running animated sitcom makes perfect sense.

Rogen says as a writer, The Simpson's "always seemed like the Holy Grail."

The episode titled "Homer The Whopper" kicked off the 21st season this past Sunday. Rogen played a trainer who helps Homer Simpson get into superhero shape to play a character created by the Comic Book Guy, named "Everyman".

"We wanted to comment on how Hollywood generally ruins these movies. The whole joke is Homer is cast to play a guy who's an everyman and they try to make him into this physically fit guy," Rogen said.

After comedian Ricky Gervais, Seth is the only other celebrity to write and voice for the show.

What an achievement! Congrats!

[Image via WENN.]