It’s Tickle-Me-Wiggly, the toy everyone wants in the StarKid Black Friday comedy-horror musical. My daughter backed the StarKid Kickstarter and we're both fans of their musicals.
Where you can buy online
Direct from us here - see products featuring this design.
Elsewhere online:
TeePublic (US and UK)
RedBubble (US)
Threadless (US)
NeatoShop (US)
Etsy
You can find the design on t-shirts in most stores, but also on other products depending on the store (e.g. hoodies, mugs, stickers, notebooks, phone cases, greeting cards, cushions, socks etc).