I was wondering if a model in the source engine could have essentially 2 textures, 1 on top of the other and based on animation you show/hide the appropriate "skin" as a result. The goal was to have a decapitation animation with actual head removal while playing with the custom model as your default. I've gone so far as to replace a dead ragdoll on death with a headless ragdoll body and it's head but the ragdoll itself takes up a lot of network overhead. If the player were playing with the model and it's "custom" death animation played out for specific weapon deaths that would take out the need for killing the entity and replacing it with a prop_ragdoll. I just don't know that the source engine is robust enough to have a model that can detach a piece and maintain physics, etc. Or, if you'd have to play with a head that is already detached, but set to the body as a parent entity, then detach on specific death.
Just really spit-balling this at the moment.
Just really spit-balling this at the moment.