SPECIAL... but it really does move and protect him.. it is either Sterek or Steter...I think it was Steter... It protects him and at first bites Peter or Derek.... Scott always humored him, but by the time frame of the fic I believe he was not being a good friend anymore.... Thank you in advance for finding : )
FOUND! Thank you chris7100! Link is in comments!
"Dioskouroi" in Cywcross's "Steter Drabbles" at
https://archiveofourown.org/works/4426598/chapters/10057796