Nightmare Amalgams are a unique kind of minion card in Hearthstone Battlegrounds. They are capable of having synergies with any type of minion, making them a very versatile card to purchase whenever possible.
How to Use Nightmare Amalgams in Hearthstone Battlegrounds
There are two unique buffs you should aim to pickup for your Nightmare Amalgams. Toxfin and Annoy-o-Module will be an instant purchase to buff up your Amalgams. Toxfin gives the poisonous effect to a friendly Murloc, which will kill any unit hit by it. Annoy-o-Module will combine with your Amalgam and give it Divine Shield and Taunt.
It may be a better idea to pick up only 2 Nightmare Amalgrams, as having two minions with Divine Shield and Taunt will often be better than a single upgraded Amalgam. Keep in mind there may be some situations where upgrading will be the correct play.
Nightmare Amalgam is a powerful tier 2 minion, and some people may consider it to be the most overpowered in its tier considering it can be buffed by anything and has the highest base stats of all tier 2 minions.