You take firm hold of the bat and see what you can do. Looking at the bat you would say it has about two or three flesh units, one unit of blood and veins, a set of tiny organs, about one unit of tiny bones, and about a unit of skin and membrane.
You flex your magic a little bit and see that you can rearrange the flesh and blood vessels pretty easily, the bones require a bit more effort, but you can extend contract and bend them, the organs are pretty delicate however, you think if you tried to change them to do different functions or messed with them a whole lot, you'd run the risk of just melting them.
It's pretty easy to remove parts, and theoretically add them onto another living thing. This is one of the key elements of the fleshmancer, creating living tools to overcome challenges. To that end, you consider making a pair of living bat sandals. That's a very fleshmancer thing to do! However, looking at your one bat, you realize you wouldn't have enough components to keep the sandals alive. Which leaves you with two options in that regard, catch another bat and make some nice warm sandals, or craft a pair of sandals killing the bat in the process. Of course you could try and store the bat in some way and keep it or it's parts for later. You briefly consider just attatching the bat to yourself, but you know that fleshmancy doesn't work very well when cast on oneself. Jim decides that's something he's only going to do in extreme situations, due to the likelihood of him dying or being permanently disfigured.