Cnidrion can only spawn where Underground Desert background tiles are. Underground Desert biome is not defined by height, but rather the preence of these very background tiles. See: https://puu.sh/x7Fep/0e4faf993e.png https://puu.sh/x7FgN/248635ecea.png https://puu.sh/x7FdM/91891a02db.png https://puu.sh/x7FiF/c078cdce1a.png Orcao (talk) 19:49, 11 August 2017 (UTC)
Minecat07 (talk) 08:12, 12 August 2017 (UTC)You are correct, but you also can just remove a few sand blocks at the surface and the background tiles will be there. This can allow the cnidrion to spawn, thus making people think it can also spawn on the surface. It can easily happen if you're flattening the area to farm sand elementals.Minecat07 (talk) 08:12, 12 August 2017 (UTC)