Yeah this is a known bug we couldn't get fixed in time for release - it's taken a bit of a back seat due to low priority compared to other bugs but I'm still working on it
If you're curious why this is happening, Grouch uses the Farmer NPC dialogue, which uses the humanoid chathead. But, because Grouch is a croc his chathead uses slightly different anims.
One other character that sometimes uses an old chathead ani, is Armadyl in the new Eye of Het 2 miniquest. He had a few of those ones where it does a bit of speaking (like how it use to be) and pauses and looks like the croc here moving his head side to side. Im guessing it uses the same ani's ;)
That one has a fix ready to go out - as yeah, Armadyl doesn't have quite the same range of chathead anims as humans do :)
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