:censored: :rant: :whistle: :cheer: :cheer:
I believe that's an issue with the model's nulls and/or boning. You most likely need to edit those and place them in the correct positions in order for the stuff to disappear.
Whoever enveloped those models didn't hide the bone_root/pelvis correctly and it's frozen and visible at the base of the model. You can re-envelop the models or you can simply find some other model to use.