Anyone know what this could be?

Just been for my usual midnight run along the beach and when I got home noticed this thing had randomly appeared under my little finger.
It's quite solid but feels like it could be pierced, worried its a wart hoping its a blister any ideas people?

gyazo.com/252d18ef1a8d64ad50869f3668569e5e.png
It looks like a wart
It looks like a blister
It looks like something else I'll explain further
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+1 y
It was a blister it disappeared thanks for all your opinions.
Anyone know what this could be?
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