Ani-Shell is a simple PHP shell with some unique features like a mass mailer, ddoser, connect-back shell, bind shell, and various other features.
You can download it from the following link: https://packetstormsecurity.com/files/download/105295/Ani-Shell-1.4.zip
Source: https://packetstormsecurity.com/files/105295/Ani-Shell-1.4-PHP-Shell.html