Sesquipedalian!
Eats Luftwaffles for Breakfast
I do believe the oldest creature on my possession was a Charmander-turned-Charizard from my first game of Pokemon a rather good while ago. I do recall ourselves holding excellent adventures together, with realizing we were not permitted to turn on the ceiling fountains in Brock's gym and whatnot. Sadly, I was only able to train my good friend until Level 81 before my copy of the game decided to disappear completely. Oh how I miss that Charizard.