I Got A "VOID EGG???" In BGSI For The First Time :O (Read Description)

So. I was afking in the even area for leaves and came back after getting a drink. A few seconds later, I hear a sound from BGSI. It sounded like the sfx for pulling out a speed coil and then i saw an item was added to my inv that was Secret. I looked though it and found a "VOID EGG???". I have never seen or heard of this item so I wanted to talk about this. I bet it already has but i think less know what sound effect played when its obtained. Thanks for reading and crazy how my RNG was here lol!