Topps's Slob Stickers series was a fun little gross-out exercise that predated the very similar Garbage Pail Kids by several years. The concept was the same humorous drawings of outrageously grotesque characters with funny names.
Also, like GPK, the artwork was reused between different series, just with different names for the pictured characters; even the numbering remained the same. For example, #3 of Series 1 is Disgusting Donald; #3A of Series A is Disgusting Dom; and #3B of Series B is Disgusting Donnie. The image depicted on each is the same.
The three sets, as mentioned above, are designated respectively as Series 1 (with regular numbering), Series A (with the letter A after each card number), and Series B (with the letter B after each card number).
Although undated, the series can be dated to the 1960's due to the use of Jack Davis artwork throughout, and the fact that the pack price was 5 cents.
There is a difference of scarcity between the three series of cards; generally, Series A should be considered to command about 1.25 the price of identical Series 1 cards; likewise, Series B, the scarcest of the three, can be said to command about 1.5 to 1.75 times the price of Series 1.
The series was re-introduced to modern card collectors in 2013.