How might Animated Objects are created? These are the named monsters in the Monster Manual rather than the items in the spell Animate Object?
Golems are called out as needing to be created via a Manual of Golems, but I can't find anything specific for those Animated Objects. Also as there is no value/rarity I struggle to apply the Creating Magic Item rules in the DMG.
The accepted answer of suggested question: What are the rules for making constructs other than golems? seems lacking for this case.
I am looking for ways to apply the current rules, this has been done by an NPC but should the players decide to read up on the research he has done i'd like to give reasonably accurate figures.