The hive is an alien structure that hosts tiny little insects that will swarm out when a human gets too close or attacks it. Guess who made the concept artwork? Surprise, it's alex_bo!
Like most of our alien strucutres, the hive once was a mobile life form but evolution transformed it into an immobile host growing on walls and ceilings, so the animations will include idling, pain and death. You can animate it yourself if you want to (have a look at the acid tube animation first), otherwise we can pass the finished model to an animator.
Sure, but let's get the Spiker finished first – we might have some additional feedback for you as soon as we try to put the Spiker ingame, which might improve the Hive when you start it afterwards.
For the height, the same rule as for the Spiker applies: Since the Hive can be built on any surface (including walls and ceiling) and we are using axis aligned bounding boxes, the structure should have a roughly cubic bounding box. So in short, the Hive's main body should be roughly as high as it is wide.
For the hive, can we also have tiny buzzing aliens modeled for it? Would look much better than the 2D effect in Tremulous. They don't need to be very detailed, you wouldn't see them up close for more than a fraction of a second.
Good start! I guess for the surface you can go with a similiar material as the Spiker's leather. I feel that unlike the concept, the eyes should be on the flesh and not on the coat. (If I remember correctly they were first missing on the concept and added when it was nearly completed, so the concept doesn't really give them a dedicated space.)