I don't know if this is a tooth from every shark you've killed, or each one that's bitten you, but either way it's impressive.
Shark-Tooth Necklace price in Growtopia: sells for about 15 DL, buyers pay about 2 DL 55 WL (median of 63 offers from community Discords, past 30 days). Live price chart and the latest buy and sell offers.
Recently sold at: UEJO, OKXX, GLNPP, FBNG, VANVENDO