porcelain box with spikes

I recently bought this at a thirft store because it looked so unusual it's made of porcelain I think retangular shaped has 4 small legs is hollow and has the round hole on top . Potruding from the bottom inside wall is about 50 spikes in a round circular formation but there just long enough as to not stick out above the hole on top there made of metal and are petty sharp. There are no marks or signature. Hopefully the pictures will do more justice than my explanation

Good