css help uwu

heyy, thanks for answering my plea random citizen ;3

i would like to add the lil gif that some people have at the bottom right of their page, if anyone could help with what code I need I'll be eternally grateful! thanks :DDD

https://i.pinimg.com/originals/37/c9/14/37c914b757a05e582df60b49180b7126.gif