With this free blood spatter Photoshop brush set, you can amp up the gore even further. It comes with a variety of large-scale brushes that you can use to create realistic bloodstains in your artwork. These brushes are available for personal use for free, or for commercial usage for $10.
AnnFrost-stock is the designer.
Usage: Credit is required for personal usage.
DeviantArt’s Blood Splatter is available for download.