There are 3 different types of Pig Greate obtainable from Pigs. Pig Grease is used to increase the chances of certain types of animals, or to brew the Animal Attractor Potion.
Pig Grease
Pig Grease is obtained from Tier 1 Pigs. It is used to make Grease Shrooms, Snail Glue, Grease Stone, Grease Bone, Mineral Grease, and the Animal Attractor Potion.
Good Pig Grease
Good Pig Grease is obtained from Tier 2 Pigs. It is used to make Burnt Grease and the Animal Attractor Potion.
Great Pig Grease
Great Pig Grease is obtained from Tier 3 Pigs. It is currently only use for the Animal Attractor Potion.