A type of drone/entity that has rebuilt itself via using worker drone and disassembley drone parts. It is missing half of it's face due to a chainsaw impaling its visor. It has no true intentions at all, not even its information exist, It's just there. It's favorite form is "N-Sanity" for unknown reasons. While SK-99 has no eyes visible, it can still see with no problems and it cannot be harmed or killed in anyway possible. It is a threat to all drone-types due to having no info and its abilites