Irving Pal is the principal of James K. Polk Middle School in season's one and two, but is never seen or mentioned until Season 3. In season three, Mr. Wright is appointed as the new principal in which he becomes the new social studies teacher. However, he does not officially step down until episode seven of season three. He is played by the late John Bliss.
In the episode "Social Studies", Mr. Wright is troubled to tell Principal Pal (who still uses his office) he is no longer principal in fear that he will hurt Principal Pal's feelings. In order to make him realize it, Mr. Wright places his desk and office materials in the hall outside Principal Pal's office. Pal ignores Mr. Wright's obvious attempts until Mr. Wright gets fed up and tells the Principal he is no longer principal. Principal Pal admits to Principal Wright that he was already aware but was testing him to make sure he could make tough decisions. Later in that episode, Principal Wright tells the always sleeping Miss Knapp (who is a little older than Pal) that she is allowed to retire. Despite being elderly himself, Mr. Pal takes her spot as the social studies teacher throughout the rest of season 3.
In the episode "Halloween", Ned and company are assigned to throw a Halloween party to which they have no idea how. Throughout their worries, Principal Pal attempts to scare them only to fail. Eventually, Ned, Cookie, Moze, Gordy, and Vice Principal Crubbs construct a hallway of terror which is controlled by a switch to change the intensity of the horror. Eager to try it, Principal Pal is the first to enter. However, the intensity is turned to full power to which Principal Pal collapses from the shock. Horrified, the group checks for his pulse and heartbeat only to find that he is dead.