Boris was a loyal member of BloodClan, that is, until he met Bamboo. The bubbly kittypet was a delight to scare and put on edge. They made a deal: Prey for Boris teaching him how to fight like a street cat. And without them realizing, they fell in love. But Boris was still part of BloodClan, so his loyalty compelled him to fight against their enemys - a fight he would not survive. He died in Bamboo's arms.