We all are wondering how BlackBeard has 2 devil fruits , The one with the Darkness and the quake one that belonged to WhiteBeard .
I guess the first one wasnt the Darkness one , it was a zoan and its a 3 headed dog like the one that
was in thriller bark , so each head can eat a devil fruit , BlackBeard ate 2 Devil Fruits after the Zoan one , so he can still eat one more Devil Fruit.
There is also two other evidences that its a 3 headed dog.
First : The BlackBeard Jolly Roger
It has 3 skulls which refers to the 3 headed dog or whatever animal it is.
Second : Shanks Scar
When Shanks went to see WhiteBeared he told him that the scar one his eye was made by BlackBeard , and they looked like claws and the 3 headed dog has claws too.
Thank you for reading please comment your opinion in my theory .
I made up this theory from my mind , it doesnt have to be true and its not copied.