Spinner and Mutated Rahkshi?

How were the Rahkshi that attacked Spinner and his Toa Team mutated? That is, how did they differ from regular Rahkshi? What caused the mutation, was it a Makuta experiment or unintentional?

Wait, how do you even mutate Rahkshi anyways? Were the Kraata that were used to make them mutated or something?

Bohrok Kal mutagen maybe?

We only know of one Kraata-Kal, and he’s also a Dark Hunter. I don’t think that Spinner would enjoy working with him if they were that similar.

Then again, TSO is not very sensitive to what his agents like and don’t like.

True, though I always got the impression that Kraata-Kal was unique.