Update: Lady Gaga won this round. Click here to vote for her Little Monsters in the Semi-Finals!

In Round 1 of March Madness -- in which PopCrush readers vote for the best fanbase -- Katy Perry's KatyCats are up against Lady Gaga's Little Monsters. While we're well aware that both groups are made up of some seriously die-hard fans, only one can come out on top and make it into Round 2. So, who will it be: KatyCats or Little Monsters? Cast your votes!

Katy Perry's KatyCats are one of the biggest and most unstoppable fanbases out there. In fact, as of this post, the "Roar" singer has 66.4 million Twitter followers -- more than anyone ever in the history of the social networking site. That's more than 60 million Katy Cats! Pretty freaking impressive. Of course, Katy's fans do so much more than just follow her on Twitter -- they connect with her on every level, as does she with them. Who could ever forget the moment in her documentary, Katy Perry: Part of Me, when she gathers up all of her courage to perform for fans even though she had been sobbing her eyes out just moments before? Those are the kinds of things that KP does for her fanbase -- because they mean the world to her.

There's no question that Lady Gaga's Little Monsters go hard. Case in point? Oh, just the fact that Mother Monster swept the 2015 PopCrush Fan Choice Awards with a whopping seven wins. While one Little Monster in particular gave the entire fanbase a voice thanks to the goldmine that is "YASSS Gaga," Gaga loves her fans for their bold individuality and the fact that they're not afraid to be themselves. Plus, she even has a tattoo dedicated to her die-hards -- how amazing is that?! Paws up, Little Monsters!

Which fanbase has your vote? You can vote for either KatyCats or Little Monsters once per hour until the poll closes on Tuesday, March 17 at 3PM ET. The winner of this round will move on to compete against a different fanbase in Round 2. Happy voting!

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