I was in a D&D campaign run by my friend Fisk ( largoes). After I started playing with Vee, he got his own little group. Yellow and Leaf were part of Vee's party, although they were NPCs and were played by Fisk. My campaign has since ended, but the impact still lasted.

Yellow, in turn, was inspired by an older version of Vee. He could change into various Eeveelution forms at will. He still can, but formerly the separate forms were basically separate people. Yellow, obviously, was the Umbreon form. I offered him for Fisk to adapt as they wished, and it turned out great.

Commissioned art! Artist is:  largoes (original post)