Nope. Just... nope!
I'd thought those Russian circus bears who ride around on tricycles were mostly just in cartoons (or at least a lot smaller than they appeared), but this video proves me wrong! How much did they pay these models? It's an impressive shoot: from the array of props they dragged out into the woods, to the tolerant models who never so much as shiver. (That brings to mind a few models I've shot *indoors* at room temperature who complained incessantly about "freezing".)
As Siegfried and Roy can attest, giant wild animals can still be dangerous, no matter how tame. I'm glad this worked out for everyone, and it's an awesome video on many levels, particularly the behind-the-scenes elements... but, don't try this at home! You'd never find a bear that big anyway.
(On second thought, I would totally do this -- with a bearskin *rug*.)