Is the truffle and Cyborg NPC in the IOS version? If so, does the truffles house need to be in the mushroom biome?
The conditions for Truffle to move into a house are the same as those for the PC version, it will only move into a house in a Mushroom Biome. However, it is possible to create and artificial Mushroom Biome on the surface for it to live in.
For more info on creating an above ground Mushroom Biome, take a look at these other questions: