A child (usually a bastard child) deliberately conceived for the sole purpose of acquiring monetary handouts and other unfair perks. Usually born to welfare queens, illegal immigrants and other parasites.
When the Jackpot Baby is not a bastard (which is rare), it is usually conceived for tax breaks.
Occasionally, a person with wealthy parents will deliberately produce a child when promised large sums of money in exchange for producing an heir. However, the previously mentioned bastard child is the most common.
Jackie: "I'm working at McDonald's during summer vacation. Where are you going to work?"
Shameeka: "Work?? Girl please! I'm gonna have me a Jackpot Baby so I can get on the 'fare, fuck that workin' shit! I ain't gettin' my hands dirty fo' no motherfucker!"
Jackie: "Oh. Uh, ok. So who's the daddy going to be?"
Shameeka: "Whoever, don't matter, long as I get a baby so I can get that check is all I care about."