The pop-ups are intricate and the cover in all its scary, shiny glory, is almost 3-d itself.
As with some of the more intricate pop-ups, you will need to check the workings before you gift it to your young predator-lover; the polar bear pop-up in my copy needed a little TLC before it worked properly. Most of the 3-d swinging pop-ups look wonderfully realistic, but the eagle's wings looked broken rather than "in flight."
This is a great book. I will, however, reiterate that it's probably for the kids old enough to read it (9-12)...not because it's too "scary," (what 3 or 4 year old doesn't like a good Dino or Shark? They can be pretty scary) but because the pop-ups won't weather rough treatment. Probably not a good choice for reports because of the amount of information, but great to entice young scientists into further research.