Interestingly, as written the pile of bones can be any pile of bones, since the Humanoid restriction parses to only being applied to the corpse section, confirmed in the Sage Advice Compendium for 5e (the wording of the spell has not been substantially changed in 5.5 for that part, only changing what the group does when you don’t issue a command. Though I don’t think that’s included in 5.5’s SAC so far). So if you have enough, like, chicken bones to arrange into the size for the skeleton statblock, that RAW works.
Interestingly, the Playstation one officially isn’t the letter X, it’s “Cross” according to Sony. But pretty much no one ever actually uses that name.