Place a skull against a block and start breaking it. You'll notice that the block crack doesn't quite resemble the skull itself as cracking, but rather, the block outline itself where the skull is completely ignored.
[media]Notice after MC-183915 was fixed:
Now, in some cases, multiple crack layers appear once the skull starts cracking.
Additionally, the cracking layers can shift on the skull while the animation is playing.
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Affects 1.16 pre7
same sort of thing with the bamboo sapling. The cracks go past the hitbox
I can confirm in 20w46a.
Can confirm in 21w03a.
Can confirm in 21w06a.
Can confirm in 21w15a.
Can confirm in 1.18.2 and 22w18a.
Can confirm in 1.19.2.
There is also a bug with the hitbox of the skull.
You can see it in the pictures.