I have a Triassic Egg in play with two charge counters on it. After my opponent declares his attack, I sacrifice the egg to bring a Benthic Behemoth into play to act as a blocker. In response, my opponent activates his Icy Manipulator to tap my Triassic Egg. I believe this effectively stops me from being able to bring out my Behemoth as the Egg is "turned off" before I can use its activated ability (if I understand the stack timing correctly). Wanted to double check though since the activation cost of the Egg is , if that makes a difference or not. Also, do I have to reveal the creature I am bringing into play via the Egg before my opponent has to decide whether or not to use his Manipulator to turn off my Egg? Thanks.