With Butch installed, whenever one of the following mobs is killed, instead of its drops, it will drop its carcass. The carcass can then be put into a Butcher Block with a Butcher's Blade in the blade slot in order to Butch it. Once a carcass is butched, it will reveal up to 4 drops in the slots on the right. The amount is semi-random, but most of the time you'll get at least one item, and sometimes up to 6 for others. The new items can be used in some useful way. For example, with tallow from cows, you can make candles or torches.
Cow
Horse
Sheep
Squid/Glowsquid
Pig
Rabbit
Goat
Chicken
Llama
Turtle
Butch also adds various extra items to compliment some of the new mob drops, as shown below. There are 4 stages of portable inventories from pouches to backpacks. There's a new bowl made from turtle scute and glue to hold your new turtle stew, new decorative balloons that can be placed midair, and a slingshot you can use to finally give llamas a taste of their own medicine.
Have ideas for some of the other mobs in the game, or something I should change with the ones already added? Let me know, I'm always open to feedback. Also, you might note that the art is not good. That is because I made it. If you have the desire to contribute better art, I'm also open to that. I will say that I'm sticking to 16x though.