It is possible to craft mobs, yes. But I found a problem in which if they move before the crafter removes him from above the table, it “fail” and starts the next craft, leaving the mob there forever stuck.
What I did in the Archipelago mod (not in the public version yet) was add a “doll” item crafted by the herbalist. The doll has a timer of 2 seconds, which is enough time for the crafter to grab it and put on the floor. After this timer, it will turn into a real mob, the cocoling. (DT: Desert Critters!)
Maybe you can try something like that.