How to get mob fragments and where are they stored?

[Kotovik21]

Hi!
I'm wondering about mob fragments, blaze fragments in particular. I killed about 100k blazes and I didn't get a single one or so I think. I'm not sure where they are stored. I want to buy a blaze mob suit so any help would be very appreciated.
Thanks!

 

[obvLesley]

It is currently buged and only very few ppl know how to get them, and they are abusing that bug to sell mob suits for like 100m+ exp each.