Hoops & Yoyo Ruin Christmas (2011)
The special is stylized to look kind of like it was done using paper cutouts, but it's all clearly cheap CG. The plot follows the two title characters, along with a mouse, as they somewhat accidentally stow aboard Santa's sleigh, then fall off while he's flying through a wormhole and get flung back in time. The wind up interfering with a young Kris Kringle and nearly destroying Christmas forever.
This thing isn't without charm. The wormhole sequence is interesting if derivative, and the young Santa is handled pretty well. The special actually picks up some momentum as it follows him to a toy competition, which he essentially forfeits to give his entry to a poor girl he meets. If they'd have followed this through to its natural conclusion - having Kringle realize his calling on his own - I'd be summarizing this thing in very different terms. However, the girl turns out to be some kind of spectral fairy queen in disguise, and she magics Kris into his new role with a wave of her hand.
With its tension gone, the special wrapped up without a shred of meaning. It wasn't unpleasant to watch - there were enough jokes to keep it entertaining - but the whole thing felt like it was put together by committee; a better committee than most Christmas specials get, but a committee nonetheless.