Madballs were a series of toy rubber balls created by AmToy, a subsidiary company of American Greetings in the mid-1980s. The toys incorporated gross-out humor in the vein of Wacky Packages and Garbage Pail Kids. Each ball had a character synopsis and an odd name.
The head-popping Madballs were similar to the regular Madballs figures, but came with poseable bodies with swappable heads.
Due to the popularity of the Madballs, there were many similar toys, such as:
“Blurp Balls” by ERTL – Boney Tossteeth, T-Retch, Count Have-A-Heart, Spittooey Sooey, Biff Barfball, Sharkey Skullsquert, Retch-A-Rat Tomcat, and Croakey Bugchuck. These toys were designed by artist James Groman with character names and editorial by Rick Reising. 
“Weird Balls” by Mel Apple – Sewer Face, Worm Skull, Wart Hog, Spit Ball, Shrunk Head, and Snot Nose
“Odd Balls/Ugly Balls” by Bonkers – Dirty Devil, Blood Bulge, Lace Face, Evil Knievel, and Ugly Ball
“Spit Balls” by Lanard Toys – Sharky, 20/20, Ba-Boom, and Crybaby
These items never became as popular as their Madball counterparts.