How To Train Your Dragon 2
35 Achievements
1,000
Dragon Whisperer
Fly each Dragon for at least 2 hours.
25
How to unlock the Dragon Whisperer achievement in How To Train Your Dragon 2 - Definitive Guide
The easiest way to get this is to wait until after you've completed everything (completing all events to gold and getting the racing paints). After that's all done, you'll need to just leave your game running while your dragon is just flying around.
I have no idea if being in splitscreen counts towards 2 dragons at once, but I did unlock the achievement while in splitscreen. So in the worst case, being in splitscreen still only counts for player 1's dragon.
Glitchy
This is the rarest trophy according to many trophy tracking sites, even though finding the tokens and competing in all four tournaments should take roughly 2 hours (about 30 mins for the tokens and about 20 mins for each tournament). As a result, I believe this trophy is glitchy. I played some 1P and some 2P and although the racing paints unlocked for both dragons when using two controllers, I flew with each dragons for much longer than 2 hours each before the trophy popped. My guess (please let me know below if you have a different experience) is that either it only counts flying in 1P mode, or that it doesn’t count time from tournaments/events towards your total flying time. Either way, you should expect this to be your last trophy unless you are willing to just leave your system on with your dragon flying into walls for hours at a time.