The 28 Best Guest Voice Actors On "Adventure Time"

These stars weren’t afraid to get a little weird in the Land of Ooo.

1. Neil Patrick Harris as Prince Gumball

Getty / Jason Kempin

Cartoon Network

 

Of course, he sang.

2. Matthew Broderick as The Dream Warrior

Getty / Cindy Ord

Cartoon Network

 

Not even sure what’s going here.

3. Mark Hamill as The Fear Feaster

Getty / Michael Buckner

Cartoon Network

 

Since portraying Luke Skywalker, Hamill’s had a long and illustrious career as a voice actor, most notably his role as The Joker in Batman: The Animated Series.

4. Laura Silverman as Ethel Rainicorn

Getty / Noel Vasquez

Cartoon Network

 

Silverman, sister of comedienne Sarah Silverman, plays the perfect doting mother.

5. George Takei as Ricardio the Heart Guy

Getty / Frederick M. Brown

Cartoon Network

 

Few do creepy better.

6. Henry Rollins as Bob Rainicorn

Getty / Frazer Harrison

Cartoon Network

 

He also voiced this ill-tempered cookie man.

7. Andy Milonakis as Neptr

Getty / Michael Buckner

Cartoon Network

 

He even rapped.

8. Maria Bamford as Wildberry Princess

Getty / Karl Winter

Cartoon Network

 

It was great seeing Bamford’s signature dark humor in cartoon form.

9. Steve Little as Peppermint Butler

Getty / Larry Busacca

Cartoon Network

 

Little plays Stevie on Eastbound & Down.

10. Ron Perlman as The Lich

Getty / Frazer Harrison

Cartoon Network

 

Appropriately enough the Hellboy star voices one of the show’s scariest characters.

11. Miguel Ferrer as Death

Getty / Kevin Winter

Cartoon Network

 

You may remember Ferrer from his role on Twin Peaks as the cranky FBI Agent Albert Rosenfield.

12. Andy Samberg as Party Pat

Getty / Paul A. Hebert

Cartoon Network

 

Party Pat likes to, well, party.

13. Brian Baumgartner as Georgy

Getty / Taylor Hill

Cartoon Network

 

You may recognize Baumgartner as Kevin from The Office.

14. Donald Faison as Baby Snaps

Getty / Jason Merritt

Cartoon Network

 

The Scrubs star plays a heartbroken cookie.

15. M. Emmet Walsh as The Cosmic Owl

Getty / Angela Weiss

Cartoon Network

 

Walsh, one of the most revered character actors in Hollywood, participated in this epic beat box.

16. Toby Huss as Booboo

Getty / Imeh Akpanudosen

Cartoon Network

 

Huss is best known for playing Artie, the “Strongest Man in the World,” on The Adventures of Pete & Pete.

17. “Weird” Al Yankovic as Banana Man

Getty / Jason Kempin

Cartoon Network

 

Yes, he sings.

18. Justin Roiland as The Earl of Lemongrab

Getty / Frederick M. Brown

Cartoon Network

 

Roiland is best known for his work on the animated show Fish Hooks. One of his biggest strengths is screaming.

19. Roz Ryan as Cake the Cat

Getty / Moses Robinson

Cartoon Network

 

Ryan also voiced Thalia in the Disney movie Hercules.

20. Paul Reubens as Ruler Gnome

Getty / Larry Busacca

Cartoon Network

 

The Pee-wee Herman star does a great supervillain.

21. Emo Phillips as Cuber

Getty / Frazer Harrison

Cartoon Network

 

The kooky standup narrated the episode “Five Short Graybles.”

22. Stephen Root as Grimby

Getty / Valerie Macon

Cartoon Network

 

Known for his role as Milton in Office Space, Root delivered this immortal line.

23. Kerri Kenney-Silver as Old Lady Princess

Getty / Frazer Harrison

Cartoon Network

 

Kenney-Silver is best known for her role as Officer Wiegel on Reno 911!.

24. Brian Posehn as the Leader of the Businessmen

Getty / Michael Loccisano

Cartoon Network

 

The standup comedian is best known for his role as “Brian” on The Sarah Silverman Program.

25. Michael Dorn as Gork

Getty / Kevin Winter

Cartoon Network

 

Audiences may recognize Dorn’s deep voice from his role as Worf on Star Trek: The Next Generation.

26. Bobcat Goldthwait as Ed

Getty / Angela Weiss

Cartoon Network

 

Dat VOICE.

27. Lou Ferrigno as Billy

Getty / Brad Barket

Cartoon Network

 

You need big muscles to be this awesome.

28. Biz Markie as Snorlock

Getty / Ilya S. Savenok

Cartoon Network

 

Only Biz could pull off this sexy jam.

Check out more articles on BuzzFeed.com!

Facebook Conversations
          
    Now Buzzing