Winter Wonderland Champion Trophy in 3D Ultra MiniGolf Adventures 2
Winter Wonderland Champion
Win the Winter Wonderland Tournament.
How to unlock Winter Wonderland Champion
As the description states you must win an 18 hole match on the Winter Wonderland course. Note that this can be done with two controllers in offline 2-player mode if you're having trouble beating the computer. Just make sure your main account wins and the trophy will unlock. This can also be unlocked in online matches.
Here are some videos of the course in case you're having trouble on any specific holes. They're not all hole-in-one shots, but they should be more than enough to help you score -5 for the round.