I was thinking the other day it could make for some interesting game play to have a liquid bacteria orb alien - much like the screenshot below, only the nucleus would be infested and baterial looking.
if someone did a quick edit of this or own concept that would be awesome


The idea would be this alien would be completely immune to all weapons, but its weakness would be the flamethrower and grenade launcher, and normal grenades too - anything that is hot enough to evaprote the bacteria inside (heat)and to distort the fluid (explosion).
It would very slowly float, slither or even roll around like a big ball of baterial jelly, a slow but ever approaching terror.
Anything making contact with it would start to take damage, and if anything was to go inside it (marines, turrets, medpacks, buildings, bullets) it would get absorbed by the bacteria, restoring the health of the orb. Perhaps even temporarily increasing the max health.
This would make it very affective as a siege weapon against turret farms or heavly fortified locations, as it would absorb the brunt of the bullets and creating a physical shield for other aliens to hide behind.
It would encourage the marines to work as a team, the flame and grenade units would try to take it out, while the machine gun and shotgun units would try to hold back any other aliens which are trying to take out the flame and grenadiers (encouraging alien team play)
Visually you could do some very amazing things.
For starters all of the watery type effects like reflection and refraction.
you could have optical heat wave effects around it etc.
Not to mention the physical warping of fluid body from interence by bullets and explosions, touching surfaces and buildings, other aliens would mold the shape of it.
Of course being transparent like dirty jelly, when a marine or build, items etc get absorbed, you would be able to see them inside for a while , not a gory/bloody way but in a way that makes them dissolve and dissappear like when people are vaporised in 60's sci fi shows
Actual Abilities?
not sure which order they would be in but it could something like :-
1. create trail
using up adrenaline, the orb leaves behind a trail of filth, from which dynamic infestation starts to emerge.
2. create bacteria
using up a large amount of adrenaline the orb can leave behind a smaller pool of itself, which will stay there for a certain amount of time, damaging anything that touches it - for example you want to attack a res tower, so you leave a pool of bateria behind which would damage the res tower, allowing you to continue to wreak havoc elsewhere. (limited to 1 or 2 pools at a time)
3.other
can't really think of anything that wouldn't be similar other aliens abilities - maybe something to do with changing shape dunno, tentacles?
4. Resitance
making the orb extremely resistant to damage - if blown apart by a grenade launcher, the orb would spread into 10's of little orbs which like magnets would slowly return to a central point, recreating the orb again, unless flame units were to kill the individual parts, perhaps at this point even shotgun units could damage the small orbs.
i'd image pairing up the orb with abilities like silence , so couldn't hear the sloppy entitiy approaching would make it deadly, not to mention being invisible -> a group of marines walking through an area, then suddenly one marine starts float, and everyone realises he's actually started to be absorbed!
Anyone else have some ideas for abilities or other suggestions ?

