what is { ugly stick }?
Where did you get that outfit! Were you hit by the ugly stick?

Question

Answer

Imagine a stick that makes you uglier every time you are hit with it.  This is the ugly stick!  The ugly tree is an exaggerated example: a tree made of ugly sticks.

This is a well-known joke expression.

Answer

It's a joke expression "He's so ugly he must have been beat with the ugly stick"

Answer

Or you can say:  "She's so ugly she must of fallen out of the ugly tree and hit every branch on the way down!"