DOOM: 17 Easter Eggs, Secrets & References You Must Find

2. Icon Of Sin - DOOM II

Yes, even the final boss of DOOM II makes an appearance in this glorious celebration of just how far the series has come.

Located far above you when you finally descend to Hell, you can actually trigger the Icon of Sin by firing a rocket at it (seen above). Doing so will reveal an old-school boxed power-up, and inside is one of the many plush Doomguy dolls you can collect.

Sadly, although this creature contained an avatar of creator John Romero's head on a stick back in the day, there's currently no way to physically get to the newest incarnation and see if that's still the case.

If you've managed, please let me know in the comments below!