If you could only add 1 Toho Monster to the Monsterverse, which one would you add?

As the title asks - if you had the power to add just ONE Toho Monster to the Monsterverse, which one would you add and why?

Rodan, Mothra and Ghidorah are obviously excluded since they will already be appearing in KOTM.

For me, this one's a no-brainer: Gigan! Since I was a kid, growing up on the classic Toho films, Gigan has always been that antagonist Monster who I always gravitated towards. His design and abilities really kick ass and he is one of the few Monsters to actually make Godzilla bleed. He was also my Monster of choice whenever I played Godzilla: Save the Earth for PS2. The character, origins and potential for being a badass antagonist all factor in for me choosing Gigan over all the other Toho monsters.

I would also like to direct attention to KaijuWorld's awesome topic where they discuss how Gigan COULD be included into the Monsterverse - great topic if you haven't already checked it out.

So, Gigan is my pick. What's yours?