There is also "Lion king" king of turrent. Fistly appear as joke in Chapter 2 or 3 and during Sentry opera at the end of game hinting that it's real. [1]
Ahh, there is even article about it. [2]
![[1]](http://images.wikia.com/half-life/en/images/d/db/Animal_king_takeover_crop.png){kind=link}