McMahon is also one of the last "regular" contributors to begin working for STC, his first story being in Issue 97. McMahon primarily took on Sonic the Hedgehog strips written by Lew Stringer and were all inconsequential complete stories. He also drew several of the later Decap Attack strips and was brought in to the comic by Nigel Kitching, despite knowing that giving McMahon Decap to draw would lower his wages. Unfortunately, his work is seen as a major divider of fan opinion, with people often disliking McMahon's handling of Sonic characters. His Decap work has been seen more favourably.