I just watched an enormous ball of Poop consume Sweden. I've also seen the Earth be swallowed by Pubes, Steam absorb EA, and France split in two and flee from Mars before being eaten by Your Mom's Ass (which was, quite frankly, enormous). Sights like these are common in Agar.io, a multiplayer browser game where player-controlled circles gobble dots, increase mass, and feast on each other.
Agario is pretty simply to grasp. Name your circle, steer it around, gobble dots, and grow larger. The larger you grow, the slower you move, but as long as you're larger than another player, they can't consume you. You can also shed mass or split in two, useful for quick getaways or lunging attacks on other players. You can feed some of your mass to other players in teamplay, or even in free-for-all mode if you're feeling generous and want to help out the little guys. If you're eaten, your game is over and you're demoted back down to a single cell again.
It's addictive and fun (though expect a bit of lag), and is quickly becoming a hit on Twitch, both as a feature and as something for streamers to do between sessions of other games. Growing large enough to make it onto the leaderboards requires patience and a bit of strategy, such as knowing when to split to bait larger players and making good use of the corners of the screen to trap little newcomers.
Using certain names also provides your circle with an image. Name yourself a country like USA, France, or Spain, and you'll get the appropriate flag painted on your cell. You can also appear as Earth, Mars, or the Moon. You can be Doge or an 8-ball or a Satanist. You can also name yourself Nazi or Hitler and be assigned a swastika or little mustache, because of course you can, and this being the internet and all you're likely to see players naming themselves as swear words, racial slurs and gay 'jokes.' If you'd like to play without having to see images or names, you can tick boxes in the settings menu to turn them off. There's also a spectator mode if you just want to watch, and like I said, it's becoming popular on Twitch as well.