Pokedex entry: A mysterious seed within the syrupy apple resonated with the energy of the Mega-Evolution. Now unveiled, the sinister ringing emanating from it united the capricious Syrpents and made them exceed their power.
Some versions of the legend of the Yamata-no-Orochi depicts them with a bell (especially Okami's one, which I especially wanted to make a reference to), so here is an apple-core one!
And to make them a bit more "evolved" the Syrpents who are not the leader gained little apple leaf-like hornes.
by MentalyDraw