From WikiBrite: The Rainbow Brite WIki
Plock is a traveling salesman, who appears in Rainbow Land to purchase the Color Caves from the Sprites. He fools Twink in to believing that the Sprites can plant common rocks and grow Color Crystals. Once he got the deed to the caves, he began to charge admission. However after meeting Murky and Lurky, he changed his tune, returned the Color Caves to Rainbow Land, and flew away in his Rocket Horse pulled carriage. Before he leaves, he reminds Twink not to be fooled again.
