The title refers both to the petty insults of the school election and the literal mud golems Angor Rot uses to test Jim's skills.
Jim finds himself nominated for Spring Fling King, competing against Steve Palchuk and Eli Pepperjack. This arc serves as a metaphorical "mudslinging" contest, as candidates must propose themes and win over the student body. Watch Trollhunters - s01e15 Mudslinging
Critics and fans often highlight a scene where Angor Rot watches Jim and Barbara argue from outside their home as a "brilliantly done" way to show the emotional distance growing between mother and son. Behind the Scenes The title refers both to the petty insults
The episode follows two distinct storylines that eventually collide: Watch Trollhunters - s01e15 Mudslinging