Out of all the characters Mutt and I have created, Hedge would have be my favourite.
He's a realist trapped in an unrealistic children's cartoon, constantly getting dragged into increasingly illogical and life-threatening situations by his 'friends' who, in typical cartoon form, always make it worse.
For the longest time I was having so much fun writing him that I couldn't see the big problem with his personality... he was a complainer.
It was only when I finally stepped back that I saw that, in the context of an entire episode, he spent 90% of the time whining and being generally unlikeable. Bewildered that I didn't see it before, I realized that just because a character is fun to write, doesn't mean they're fun to watch.
It applies to more than just complainers too. Sakura from the popular manga/anime Naruto attracts a lot of hate from fans because all she ever seems to do is cry about some guy who is clearly a complete ass and never even liked her in the first place. When all she does is cry it gets really old, really fast.
But one character that keeps beating the same drum over and over again yet works is Bender from Futurama. Every episode we can count on him to be the biggest possible jerk to everyone around him for no good reason... it should make him unlikeable. But then I realized that he's more than that. Beneath his jerky exterior he's like a child, vulnerable and completely helpless. This additional quality makes him endearing and cancels out his otherwise detestable traits, making him likeable.
So it wasn't that Hedge couldn't be a complainer, it's that he had to be more than a complainer. In Hedge's case the solution was in emphasizing his passion for boring, safe things. Where before being trapped in a cage could only ever result in him complaining, now he might become fascinated by the rare type of knot used to hold the cage over a volcano. It prevents him from becoming too repetitive.
I guess you could say I learned that adding dimensions to a character makes them multi-dimensional! See Mum? I'm learning!