It was supposed to be a happy time, but it wasn't. Santa was really pissed.
It was Christmas Eve and NOTHING was going right. Mrs. Claus had burned all the Christmas cookies. The Elves were bitching about not getting paid for the overtime they had put in while making toys, and the reindeer had been drinking all afternoon and were dead drunk. They had taken the sleigh out for a spin earlier in the day and crashed it into a tree, breaking off one of the runners.

Santa was beside himself with anger. "I CAN'T believe it! I've got to deliver millions of presents all over the world in just a few hours from now and all my reindeer are drunk, my Elves are on strike and I don't even have a Christmas tree! I sent that stupid Little Angel out HOURS a go to find a tree and he isn't even back yet! What am I going to do?"

Just then the Little Angel opened the front door and stepped in from the snowy night, dragging a Christmas tree.
He says: "Yo, Santa, where do you want me to stick the Christmas Tree this year???"

And thus the tradition of Angels perched atop the Christmas trees came to pass. . . . .