Board Thread:Episode Discussion/@comment-112155-20151209000111/@comment-24484162-20151209031959

That would explain all the sacrifices HYDRA has been sending to It over the years. The reason It's been alive so long, is because it is able to possess bodies. The 'sacrifices' were just potential hosts needed to keep Its conciousness alive.

That would also mean that Its original form has been dead for centuries.