Insult used when nothing else can describe just how much of an ass someone is. Example: Dammit, Todd, you're a pimple on the ass of humanity.... And you smell bad on top of that. Not to mention your stupid haircut. And that you're fat. Or that your clothes look awful--well, they're actually a bit better since you got married again.
PIMPLE ON THE ASS OF HUMANITY
Meaning of PIMPLE ON THE ASS OF HUMANITY in English
Slang English vocab. Английский сленговый словарь. 2012