Use aquarium pumps to add bubbles to a container or prop (beaker).
Use shredded paper towels soaked in red food coloring for bloody flesh to stuff into body parts for a good effect.
Use corn syrup and red food coloring for blood effect.
Make sure if wearing stage makeup, powder you face afterwards to set the makeup. This will soak up the grease and cause it not to smear.
Fill a non-powdered latex glove with water, and freeze it. Then when it is frozen, cut away the glove and use it for a float in your punch bowl. (You can use red Kool-Aid for a bloody hand effect.)
For a glowing toilet, take some glow sticks and tape them under the rim. This is kind of gross, but a great effect.
