It's a little-known fact, but Rath didn't actually become a karate instructor until his early 30s, when his old master retired and entrusted the dojo to him. Before that, he was making a living as a personal trainer in the gym he used to go to (and still does).

Being as close with Waylon as he is (to the point where some of you are no doubt wondering if they're dating already), Rath is quite keen not just on training him to become an even better martial artist, but also on drawing on the experience from his previous job to turn the gecko into a very swole and very tough lizard. The fruits of that labor are quite apparent by this point, even if it is a glimpse into the future (present-day Waylon is in his late 20s, this Waylon is probably approaching his mid-30s already -- Rath's turning him into quite the hot kung fu daddy).

Waylon belongs to  wccwy
Art by kidrhinoboy
See alternate version here