You can buy a bloody or skull hand at any halloween decor place or even walgreen's. We found this glass jar at a good will and filled it with dirt from outside then placed the fingers in. Great addition to any scary Halloween table decorations.
Use a side table to hold the work of a mad scientist. Fill a few glass vessels more than halfway with colored water (mix 3 drops green or 1/2 drop red food coloring in water; add a few tablespoons milk for murkiness). Peel off outer layers of a cabbage head for a brain specimen; use a fennel bulb with the fronds cut off for a heart. Read more at Marthastewart.com: Halloween Party Ideas for Kids and Adults - Martha Stewart