Block and Tackle are two large boys who are in the Henchmen stream, affectionaly know as 'grunts', they enjoy tormenting newbies to H.I.V.E. especially Alpha stream students. Two of their major victims are Nigel and Franz, they also pick on Shelby, Lucy and Laura , though seem to avoid Otto and Wing after they saw Raven protecting them.
In the Overlord Protocol the Contessa puts them under mind control forcing them to help her take over the school, she uses them to try and take out Shelby and Laura who where trying to deliver an urgent message to Dr. Nero, warning of the attack on the safe house in Tokyo where Otto and Wing were.
She uses them again to plant a bomb in the geothermal core which houses the main part of the volcano, they, along with Colonel Francisco are foiled by Nigel and Franz (suprisingly).