I just woke up with this thought in my head. I wanted to make it longer but it turned out like this.
As Dipper, Mabel, and Soos sat in the living room of the Mystery Shack decorating the Christmas tree (which Stan had chopped down and stolen from Manly Dans yard.) Grunkle Stan walked in with 3 presents behind his back.
"Ok kids. And Soos. This year I managed to actually get presents for all of you!" he showed them the gifts. Dipper, Mabel and Soos's jaws dropped. Grunkle Stan never got presents for anyone.
"Ok what's the catch?" Dipper asked "Did you steal these gifts or...?" "No I didn't steal them! Sheesh you rob a store ONE time!" Stan complained.
He handed each gift to the person it was meant for. Soos opened his first, it was a stick "Mister Pines, this is a stick." Soos observed. "Not just any stick! It's a magical wizard stick from some magical wizard land!" Stan told him and tried to act all magical. Soos's eyes widened as he held the stick "I can feel the power...Magic Soos Away!" he ran around with the stick.
Mabel opened hers next and it was a soup can with the ends cut off "Congradulations Mabel, your very first telescope!" Stan told her. Mabel gasped "Wow! I can everything!" she peaked through it and saw her brother Dipper opening his gift.
"Grunkle Stan, why did you give me a cereal box with a big hole in the front?" Dipper questioned his Grunkle. "Dipper, I thought you would know better!" Stan faked shock "That's no cereal box! It's a space helmet!" he grabbed the box and put it on Dippers head "See, now your an astronaut!" Stan exclaimed.
Dipper stood there with a -_- face. Soos ran around in the background trying to cast spells.
"Grunkle Stan, did you just get these gifts out of the garbage?" Dipper asked. Grunkle Stan stood for a moment before answering "...yes."
Merry Christmas!