Fake, John Mastodon don't exist. This social network was created by Eugen "Gargron" Rochko in 2016. He use the name Mastodon, because he is a fan of the Band "Mastodon", similar of this one use the name "Lemmy" in memoriam of this musician of Motörhead Ian Fraser Kilmister, called Lemmy, died in 2015. The name John Mastodon is a misleading of the slogan Join Mastodon.