A somewhat muffled clattering sound follows Mumbo everywhere. Most Hermits just ignore it out of politeness [with Grian and the other members of the C-Team as exceptions because they're close.]
This is, of course, because since Season 10 ended, Mumbo has been a buildstone-constructed robot created to allow his brain to interact more directly with the residents of Magic Mountain Row, made to look exactly like his young human appearance with an advanced chassis.
That small cacophony is the only major tell in the disguise, but his eyes have been known to occasionally fall off, revealing the trapdoors underneath.
He also has a fondness for eating seeds now, which is why he has such large wheat fields around his Season 11 starter base.
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