All spiders have it, but they do have varying degrees of it. Mine wobbles a bit when he goes to strike his food, which causes him to miss often, and (since he won't eat f/t yet) he's been bitten twice, but not severely. I think it's better for them to be on f/t or prekilled, but getting them there is a pain I've heard that every morph has something wrong with them, but we don't know half of it. Some are more prone to getting kinks, some get the duck bill, it's just a part of messing with genetics, I think. I'm sure if you talk to Brian he'll tell you if the Spiders for sale have a bad wobble or not.