Balloonatics characters sculpted in MudBox, transported to Maya and finished up in Substance Painter.

The high poly sculpt is made first and saved for later.  The low resolution model is sent to Maya for UV mapping.  The model is then sent to Substance Painter where the high poly sculpt is then used to transfer the details of the normal map and ambient occlusion to give the effect of a high poly model.

The result is a model that looks high poly but has very few polygons and will perform well in a game.  This particular game is VR game, so low polygons is a must!