Random magma cube spawned in my tunnel (1 block wide, 2 heigh) and suffocated in the wall. I can't tell, whether it was a big one to begin with, but a medium at the very least.
So far this was a one time occurrance in my survival world. It was a fresh 1.16 world never played on a prior version.
Biome: It was a tunnel through nether rack, but I would say it was still in the vasinity of a Basalt biome
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Thank you for your report!
We're actually already tracking this issue at MCPE-46540, so I will resolve and link this ticket as a duplicate.
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