Below is a walkthrough for the Cash 4 Teeth side quest in Tiny Tina’s Wonderlands. To obtain this quest, interact with the sign on the bridge in the central part of the Weepwild Dankness.
Meet Tooth Fairy in Weepwild Dankness
Travel to the objective to find the Tooth Fairy and speak with him.
Collect 5 teeth
Head nearby to find some skeletons. Make sure to melee one then collect 5 teeth.
Collect 32 teeth
Defeat more enemies and collect their teeth.
Investigate smell
Head towards the objective then defeat goblins until you collect 38 teeth.
Return to Tooth Fairy
Head back to the Tooth Fairy and speak with him.
Place teeth in chest
Place the teeth in the chest to the right of the Tooth Fairy.
Open chest
For the big reveal, open the chest.
Kill Mimic and Tooth Fairy
Defeat them to complete the quest.