Nothing tells a horror story like body parts.
We have assorted cut off hands, feet, hearts and such. Use some of our supply of bio hazard bags and a little fake blood and you have some realistic body parts.
OK, they are not movie quality, but at a distance, they work and cover up the fake bones and they do look real.
Have a surgeon removing a heart or use a medical cooler and some ice to transport cut off fingers to be reattached.
Lots of uses for body parts in short films.