When in an apex laboratory you should expect to find mutations and experiments gone bad. which i have seen once but it was a weak monster which didn't really do anything. I suggest that you make it to where in some apex laboratories you can find Horrible mutation experiments that could be on the scale of a boss (or miniboss) and in killing them you can get an item such as bio matter giving a chance to craft a sort of upgrade for your character such as increase into your health or energy . now provided i'm not saying it be exactly like this but something on the same scale perhaps?