EXCLUSIVE: Jack Black Gets Wacky in Hilarious 'Goosebumps' Gag Reel

Jack Black shows off his improv skills and goofy charm!

Goosebumps wasn't just a fun thrill-ride for moviegoers. There was also a lot of fun to be had behind-the-scenes.

ET has an exclusive look at the film's hilarious gag reel, which goes to prove that adding Jack Black to your cast is a great way to keep things fun and lively on set.

WATCH: This Jack Black Goosebumps Interview Might Be As Wild As the Movie!

Black's turn as horror author R.L. Stine in the action comedy was a wonderful showcase for the star's manic energy and beloved wackiness, hidden behind a deadpan, straight-faced facade -- and it was those same traits that also lead to some really great outtakes.

Another factor that played a big role in some of the film's goofiest bloopers is the inherent difficulty that comes with a whole lot of intricate computer graphics -- this includes an on-set CGI coordinator (wearing a spandex green-screen bodysuit) who almost sets himself on fire.

Goosebumps is available on digital platforms Jan. 12, and comes out on Blu-ray and DVD Jan. 26.

WATCH: Jack Black Tries to Escape Giant Praying Mantis in Goosebumps Trailer