"As an actor, how important is it to know your lines?" Gad asks. "Well, that would be rule No. 1," Pullman answers.
In this exclusive behind-the-scenes clip from the White House comedy, which airs Thursday at 9:30/8:30c on NBC, Pullman comes to quickly regret that answer when Gad tries to act out some of Pullman's most iconic roles on the set.
Check out the video to see Gad's stellar alligator impression:
1600 Penn's pilot re-airs Thursday at 8:30/7:30c, followed by an all new episode at 9:30/8:30c on NBC. What's your favorite Bill Pullman movie?