Before I go, I feel I have to mention that the Wendigo story is an overall cautionary tale about greed and overconsumption
Anyone familiar with the antics of Clifford the Big Red Dog will immediately understand the idea behind Mowu: hes a Dog, and he gets very big, very fast
Meowscarada has both of these, as the entire line only needs two Energy to start striking
Its hard to say exactly why this card is performing so well, but the most likely answer is how rare it is to see a Shiny Pikachu
Baffling End is very good against them as all their creatures cost 3 or less and is one of the best way to deal with Jace, Vryns Prodigy, Uro, Titan of Natures Wrath and Tireless Tracker as it exiles the creature permanently and Abrupt Decay does not return them back unlike Stasis Snare
Only decks focused on interaction with the Lost Zone and the Lost Engine are likely to ever use Fantina