Day 10 (12/13/14): Eugene was hiding on top of the fridge.
Day 11 (12/14/16): Eugene was hanging out in one of the stockings this morning.
Day 12 (12/15/16): Eugene was in Higgins' room. He started a short story and told Higgins to finish it. Eugene has horrible elf handwriting, so I'll type what it said:
"Finish The Story!
The Story of Higgins and Eugene
Eugene was an Elf. Higgins was a boy. Eugene liked to hide. Higgins liked to"
Day 13 (12/16/16): The Elf was hanging out on Bernardo's bookcase and left a note, "Eugene was here!".