The grown-up sized Adventure Time Christmas sweater is sold out at Forbidden Planet; the Cartoon Network is only sending them to media people they want to suck up to, like the fine folks at Anorak Magazine.
But there is still a kid-size version available. In ONE size, called ONE. Whether that size is blanket-like enough to swaddle a pair of twins, or so tiny your kindergartner ends up with a bare midriff is not important. Just buy it.
Adventure Time Christmas Jumper - RED - Child - Medium, Web Price £29.99 plus one million dollars international shipping, I have no idea, send it to Anorak and have them forward it on [forbiddenplanet via @anorakmagazine]