Used an eggless chocolate cake with Nutella chocolate ganache for this cake. Unfortunately, my eggless cake was too moist that the tail (styrofoam) was too heavy with the fondant, that it began to crack the cake in half. I had to stop working on it mid way, before the whole thing collapsed. But I still think I got the essence of the Niffler.

The head and tail were made of styrofoam. The "beak" and feet are made of modelling chocolate.