The first year when he was around 10 months he was curious about the tree but didn't mess with it. Last year he made it on the naughty list for messing with the tree
He would only mess with it at night when we were all sleeping. He would bring me ornaments, sometimes in one piece, sometimes not or he would leave them at the foot of the bed. We had to start closing the bedroom door or crating him. During the day a "leave it" worked fine.
I hope he's better this year, if not I will have a tree with ornaments only at the top of the tree