The bug

Generation bug where in badlands biomes, terracotta generates in caves deep enough where its obvious its not supposed to be there (y=18 in the screenshot provided.) In this case it generated near an aquifer, I'm not sure if that's aquifer specific or it happens in other cases as well.

How to reproduce

World Type: Single Biome, Eroded Badlands
Seed: -4379485897818154837
Coordinates: /execute in minecraft:overworld run tp @s 4144.30 15.97 -120.14 -57.24 1.63