Todd Spangler NY Digital Editor Elon Musk is now using the design of Twitter itself to make hilarious (?) jokes. On Monday, without warning, the iconic Twitter bird logo on the home button of the social network’s web version changed to the “doge” of the Dogecoin cryptocurrency. (Twitter’s mobile apps weren’t changed.) The doge image (of a Shiba Inu) is part of the logo of the Dogecoin blockchain and cryptocurrency, which was created as a joke in 2013 — to mock other cryptocurrencies like Bitcoin. Musk, who bought Twitter last fall in a $44 billion deal, is a well-known superfan of the Doge meme and he has promoted Dogecoin both on Twitter and during his appearance last year hosting “Saturday Night Live.” After the change to Twitter’s web logo Monday, the value of Dogecoin rose more than 20%.