Assuming it is an instrument, and not just some sample of croaking/voice, it's probably a berimbau or guiro, each of which is commonly found producing similar croaking noises in Brazilian percussion ensemble.
Kicked myself in the head a few times trying to remember what it was called from elementary school music class. Anyway, sounds like a Guiro or something similar. The one I remember from grade school was a bit simpler, like a hollow ridged stick that you dragged another stick across to make a croaking sort of sound. I'm pretty sure it that style was called something different, but the idea is the same.
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the "no true scotch man" fallacy.