I just tried this for the first time. It seriously deformed my non-humanoid character. I created a rig for it and added all of the missing bones. Then I set the skeleton to Humanoid Rig. I did the same from the default mannequin, and retargeted the AnimBP to the non-humanoid (a little semi-humanoid robot). All of the anims it came with play normally. All of the retargeted anims maim the appearance of the character. It’s pretty funny to watch, but obviously not what I was going for. More research!