Worse Mechano-Egg but neutral? Mechano-Egg only really ever saw play because it was a mech. If you want a deathrattle minion to consistently give you big stuff you’re probably better off with Mechanical Whelp.
What's the difference between "secretly discover" and "random"? It's weird that they use the keyword discover if the player doesn't discover anything with this card.
2 main diferences, the first, is only the player who is playing the egg knows what will be summoned out of it, and being a discover limits to neutral and class dragons from the class what is playing the egg.