Dunno who's making them, but the first one I remember seeing involved combining Frankie from Foster's Home for Imaginary Friends, Vicky from Fairly Odd Parents and Wendy from Gravity Falls to create "THE ULTIMATE REDHEAD". It was rather amusing. Then we started getting knock-offs and variants (with one involving the three Kickstarter stars; Shantae, Mighty No. 9 and Shovel Knight)