Place this clip right on the reveal cut in a reaction edit, preceded by a sudden suspense sound button to set up the moment, then follow it with the eww brother eww sound button if the discovery turns gross rather than just strange.
About this sound
A split-second spoken exclamation of 'oh my god what is that', delivered as a single startled burst. It lands as pure disbelief and alarm, the kind of over-the-top shock that turns a strange sight into a joke because the reaction feels bigger than whatever prompted it.