Well, all comedic characters are either hysterical or annoying, depending on the person watching. I though Zazu was hilarious, and the hyenas a bit on the obnoxious side, but that's just me.
I really like some of the witty lines Zazu has, both in the movie and especially on broadway. Zazu's comments about Scar are hilarious in the movie. On broadway, when Zazu's in prison he comes up with amazingly sarcastic but still technically "nice" responses to Scar's pity party, such as
SCAR: Here I am at the pinnacle, but the view is bleak. What's wrong with this picture?
ZAZU: You're in it?
Also, Zazu interacts with EVERY character in the movie, with the exceptions of Rafiki and Pumbaa. Zazu bridges (albeit unsuccessfully) the generation gap between Mufasa and Simba, he bridges the hostility Scar has for Mufasa with his sarcasm, and he even interacts with the hyenas quite a bit.
Not to mention, impersonating Zazu is oh so fun.
