its not a mod. Its only transforming the vertices wrong. It happens because the original player is made up into parts so you can change each: trousers, shirt, head/hair, shoes. The peds are made of 1 part only: object. In the 2 Player missions and the LC mod the player model (which would be a result of all single parts "glued" together) is overwritten by a ped model (Claude Speed -> 1 part). The animation engine trys to change the animation for part 0 for example which would be the head, but by replacing the model, the vertex order changed and it writes weird shit. This is also possible in the other direction - and thats what happens... (Player model is reloaded everytime you go from fat to skinny, no muscles to muscles etc