A common nickname for the STD known as gonorrhea. People give this name to compare their spotty sack to Mr Tumble's spotty bag.
MrTumble'sspottybag is his bag which is a recurring weapon in the anime.

Person A: Do you have Mr Tumble's spotty bag?
Person B: Ew no gross... I use protection!
Person C: Lift your hand just like so.
Person A + B: Do you have Mr Tumble's spotty bag?
by FurryOtaku69 November 11, 2019
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