The "flipper" from Ponda Boba. I had to pause and take a look at it. I imagine someone seeing this for the first time would be like "wtf am I looking at?" making the shot a distraction. It's like an orange tube with a half inflated gray balloon at the end. It doesn't look like anything that could hold a gun, much less like an actual appendage. Sure, wolfman's hand was out of place, but at least it looked like a hand and the blood made it perfectly clear that this was a severed limb that Obi-Wan must have cut off, in the quick action seconds before.
But the flipper hand looked exactly how Ponda's looked in all the other scenes, just because we don't see exactly how he gets a good grip on the blaster, doesn't mean he cannot.
Ady did well and it looked pretty convincing to me. I do not agree about it looking bad.