This idea came to me as i was playing DoD and got shoveled by a guy prone beind sandbags. I'd like it if someone would make a Ninja pack for NS. Not for the marines, but rather for the Aliens =D
Structures: Undoubtedly the alien structures would need to be modeled into other things. I'm thinking a torch for SC, (let it light your way with SoF =] ) for MC some kind of small shrine (use it to tansfer your spirtit or something, dunno much about japanese buddhism or shinto) DC would simply be a fountan with some food in a small bowl next to it, i'm thinking the chicken on a stick or some soup. Hive would be a tree that the little skulk ninjas (spoken of down some in this post) hop out of.
Aliens: For the skulk it'd be the classic ninja in black pajamas, that moves around always crouched; the ninja would run and move with both legs and his left arm, right arm for using his dagger/shuriken things. It could throw scented beads as parasite, and then would extend his legs during leap.
The Fatty..... i have no clue.... Ninja dog or something. (I like obst's gorge in a tank for this)
Lerk would be a guy with a pipe and would just do air jumps or something. He would of course blow smoke out of his nostrils at you to suffocate the marines in the hazardous puff. And for his bite, he'd just smack you with the pipe, and Primal scream could be replaced by a "Whuaaaaaaaaa!"
Fades i think would be more of a warrior Ninja, walking up right and wearing a bit of armor (think Ninja Gaiden's Ryu) opposed to the black pajamas. He, like Ryu, would be armed with a katana of some sorts. blink would just be him jumping really well, metab can have him applying a cream or self-message(heh, not in that way). Acid rocket could be some sort of weak bomb he throws.
Finally, the Onos. I'm thinking the Onos could be a full-fleged Mounted Samurai. Armed with a large spear, and a net for capturing and dragging Marines; he would ride into battle atop a Clydesdale, which could paralyze you with fear then charge at you.
This + Jin Roh pack could be one awesome combo! Like they were the last of the Ninjas, fighting off the untraditional army. On the othe hand The Army just wants to reclaim its territory raided by the Ninjas.