i say we take off..... and nuke the site from orbit, its the only way to be sure.....

There is also the Hierophant Bio Titan and Harridan and more found on Forgeworld.

http://www.forgeworld.co.uk/Warhammer-40000/Tyranids

I believe that the tyranids in-game could go either way, they could come from leviathan or a splinter of kraken
Lore-wise Im still quite intrigued to see what could happen if the full tyranid force (including the not-yet-revealed counterparts) would enter the eye of the terror

ohhh Daemons fighting tyranides, badass scale is over 9000!!!!!!!!!!!!

The effects of the shadow in the warp caused by the whole tyranid race in the place where the warp manifests into the physical plane intrigues me quite much

Leviathan has a good, iconic colourscheme, so hopefully that'll be their pick.

i bet the Necrons would be... maybe, depends on how well the bio-weapons would do against Necrodermis, the necrons may just rebuild them selves over and over

It's interesting they haven't ever touched on this, at least to my knowledge.

A cool idea with the Tyranids would be to have the developers randomly possess groups of them so they can battle their community! It'd be so epic, you'd never know when you're about to get blindsided by an actual thinking Tyranid swarm versus a regular computer controlled one! It'd add sooo much excitement for when they show up!

Starship Troopers anyone?