From Stardew Valley Wiki
|Looks like it belonged to a postman or policeman. Either way, it's still very soft and smells okay.|
|Achievement Description:||Catch 24 different fish.|
|Sell Price:||Cannot be sold|
It may be a reference to the recurring character Harris from Harvest Moon, as in Harvest Moon 64 he was the town's mailman, and in Harvest Moon: Back to Nature and Friends of Mineral Town, he is the town's policeman.