Thiccpack

The abs OR lack thereof on a particularly fat person
Can be used to describe somebody who has visible abs but is overweight, such as a heavyweight wrestler (1)
Alternatively, it can be used to mock somebody for NOT having visible abs due to body fat (2)
Both are generally used jokingly, between friends or acquaintances.

Friend: hehe hey bro nice thiccpack
Fat guy: aw fuck off I told you I'm working on it