The mature form of Queen Draco from Fate/Grand Order Arcade, also called Sodom's Beast (hence the S) or the Whore of Babylon, the Blibilical personification of Sodomy. This particular form of Draco is used for the Beast class' representative character whenever a Beast-class Servant is pulled in Fate/Grand Order's gacha mechanic.
This tag implicates queen_draco_(fate) (learn more).