Loch

Mr. Gan Gogh is a character of the day who appeared in The Light Fantastic (EP187).

Gan Gogh was once a traveling Trainer until he saw the Rainbow Lights, a phenomenon that happens only once every twelve years, near the ruins of the Remoraidians. He attempted to draw the lights using seven crayons. However, he was unable to emulate the wide range of colors before him. So, twelve years later, he attempted to draw them once again, now using twelve crayons, but failed again. Finally, twelve years after that, he had 251 crayons at his disposal. This proved to be too many crayons, as by the time he chose one to start with, the light had faded.

In the present, with the help of Ash and his friends, he traveled to the dried up Remoraid Lake, the source of the lights. While there, he used his Venusaur to defeat Team Rocket after another one of their attempts to steal Ash's Pikachu. At sunrise, Gan Gogh and the others discovered that the source of the Rainbow Lights was the Remoraid who lived below the lake and came up once every twelve years. In the end, Gan Gogh did not get to paint the Rainbow Lights. However, he was satisfied for having learned their cause and understanding the mystery of the Remoraid.

Despite the fact that he uses crayons for his drawings, he keeps a paint brush behind his ear.

(Source: Bulbapedia)