I did, however, attempt to make the Nuclear Missile vincible in this mod.
It worked. No iscript changes were necessary (it has a death animation), and anti-air defense buildings could target it with ease. The weird thing was that the projectiles hit a wee bit above the actual missile, but that could be because it was hurtling down at them.
I also found that you could destroy your own missile.
- - - -
I attempted to make the Zerg Lurker require creep, sort of turning it into a pre-SCII Spine Crawler. This turns it into a completely defensive unit. When it died, it died, and nothing else happened. When it stepped off the Creep, it died like the Larvae do.
I'd like to try to make the Lurker produce Creep (not sure how to do this). If possible, I'd also like to make it have to be near a Creep producer (Zerg hub/defense building) in order to produce Creep (I doubt this is possible). If THAT is possible, I'd like to make it require Creep in order to Burrow. O.o
Any ideas, guys?