BloodMod

This mod simply adds blood to Minecraft. When you it any creature/entity blood particles will come out of it. When you kill any entity a puddle of blood will appear on the ground which you can remove by hitting it once. After you remove the blood a Blood item will drop which you can eat. After you eat the Blood item you will get the Blood Drinker advancement. You can also craft a Blood Bucket with the crafting recipe shown below.

After you place the blood from the Blood Bucket on the ground you can swim in it and get the Blood Bath advancement.

Please enjoy.