Hello!
A lot of folks ask me about what sort of "Grickle" objects exist out there for gift ideas. Here's a list of links to things you can get for that Grickle person in your life:
Puzzle Agent video game series
http://store.steampowered.com/app/31270/ (Puzzle Agent)
http://store.steampowered.com/app/94590/ (Puzzle Agent 2)
Exclusive prints and music from the Grickle store (Hidden People set, Children of the Night & their Dad set, Principal Skeleton, Space Sadness)
http://grickle.bigcartel.com/
Original art
http://www.gallerynucleus.com/artist/graham_annable#Artwork
Gallery Nucleus special prints
http://www.gallerynucleus.com/artist/graham_annable#Prints
The Book of Grickle from Dark Horse Comics
http://www.amazon.com/Book-Grickle-Graham-Annable/dp/1595824308/ref=sr_1_1?ie=UTF8&qid=1417711094&sr=8-1&keywords=the+book+of+grickle
Hope that helps out this holiday season!