When breaking a placed mob head, the particles sent out are soul sand textures. This works in flat/infinite worlds, both in survival/creative modes, it works with any texture pack enabled (including the default vanilla) and this has been around since 0.14 (I'm not sure if this happened earlier on) and still happens even now.
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[Mojang] Mega_Spud (Jay)
Ariel Diaz
Duplicate of MCPE-9388 – If you have not, please use the search function in the future, to see if your bug has already been submitted, as currently over 47% of tickets are being closed as duplicate.