Theory: Kog'maw is Warwick and Rek'sai's lovechild
It is too obvious. Kogmaw is always talking about being hungry and has bloodthirsty quotes despite being a wimp who just pukes and kites. Also he has the line, "Terror coming... daddy coming!" .
Warwick and Reksai must have jumped at each other and got entangled, and Rek'sai is like, "it felt good didnt it?" https://i.ytimg.com/vi/0WxYvvcb0BE/hqdefault.jpg
This is proved by Warwicks taunt to Reksai, "From a roar to a scream!". Also He says in general "less talking! more biting" and that what Reksai does, her e is Something Bite. What else could these lines be refering to?