Just played a duos battleground where my partner was Putricide and I was the hero that copies both hero power/buddy. My partner created a Flesheating Ghoul - (the undead that gains a +1 attack when a minion dies) - on my next turn, I created the exact minion - my partner created another Ghoul but with stealth.
Shouldn’t those Ghouls have merged to become golden? They were all three called “Putricide’s Creation”, all were undead and had the same abilities save for taunt, stealth and reborn.
Is this a bug or is that do not the creations become golden?
Edit to add: I passed my created ghoul.
They need to be the exact same minion
Only zilliax can merge with different versions of itself
And I don’t know if the creations can merge at all
Well that’s a bummer. 
Thanks for clarifying and responding.
Small exception with the elemental of surprise “which can triple with any elemental”.
https://hearthstone.blizzard.com/fr-fr/battlegrounds/101280-elemental-of-surprise?bgGameMode=duos&minionType=elemental
Ha !!! I just realized that the name of the card is indeed in English in the link, even in french, thanks to you !
No, Professor Putricide’s creations cannot become triples. Even if you recreate them like having the troll hero that duplicates a card in its hand by passing it to them to try to triple it. Its a hard and fast NO to any golden minions created by the professor’s hero power. I dont even think it allows the Elemental of Surprise bind with it should you create an undead elemental hybrid minion… which I dont think his power even can? Someone more in the know on this wanna confirm that for me?
I think there is no such thing as an “undead/elemental” card, the creations are always pure and only “undead”, right ?
According to the wiki there’s a couple dual type undead, but mostly there’s the og Nightmare Amalgam
Like I stated before, that’s a bummer. But thanks for clarifying that and responding. 
Pretty sure when they introduced Professor he was designed to be an Undead and Beast lobby hero. Meaning he wont be offered if those two tribes arent in the lobby, I think he can create Undead/Beast Hybrid creations. I havent been offered him in quite some time tho so someone more recently familiar with him can confirm or deny that bit.
I think it was mostly to guarantee that the lobby would have at least a bit of synergy with him.
Beast allowing deathrattle synergies, which his hero power can generate a number of interesting ones
I only got this hero once and I only had 1 partner who got this hero, so I don’t have enough experience.
I was mistaken, it wasnt Professor that was only to be offered in Beast and Undead lobbies, it was Teron Gorefiend. The guy that destroys a targeted minion at start of combat and resummons it exactly as it was when you have room eventually. I knew there was a hero that had that condition for lobbies, and Undead and Professor were released in the patch right before Teron was. So it all ran together in my mind. Sorry for my mistaken claim about the Prof.
Everyone can make mistakes, it doesn’t matter.
The main thing is to realize it.