Hello all, I hope to provide some answers to questions on how to obtain the different chibis.
Gachaclaus and Raptor Claus appear to have two entirely different loot tables for chibis that do not overlap.
For Gachaclaus, feeding mistletoe or coal results in 1 of 4 crystal types: Regular crystals (Gacha Crystal), Primitive, Ramshackle, and Apprentice grade crystals. The Regular "Gacha Crystal" is the only one that has a chance to drop chibis (Seems to be about 50% chance to have a chibi). Feeding Coal over Mistletoe also appears to have a higher chance of getting these regular crystals instead of the quality ones. There is roughly a 70% chance of getting a regular gacha crystal using coal and 38% chance using mistletoe.
Here is a google sheet that contains the list of chibis that I have gotten through testing and approximate rarity. (Sorry I don't have all statistics but I wasn't planning to make this public originally...)
Unfortunately, there are a few chibis that I was not able to get to produce through my testing so far but I will add them to the list once I find out which one they drop from.
Hope this helps!
*I would also like to mention that from 2 Raptor Claus gifts, that I got a Journeyman grade ~lvl 90 unassembled enforcer as well.