Former NFL bad ass Chris McAlister -- who signed a $55 MILLION contract in 2004 -- claims he's BROKE AS A JOKE and living with his parents ... this according to court docs obtained by TMZ.

The ex-Baltimore Ravens defensive superstar has just filed new documents in his child support war with his ex-wife Marlene in the hopes of lowering his $11,000 per month obligation.

In the docs, Chris -- a 1st round NFL draft pick in 1999 who played in the league for 10 years -- states, "I have been unemployed since 2009. I have no income."

He adds, "I live in my parent's home. My parents provide me with my basic living expenses as I do not have the funds to do so."

McAlister was a KEY member of the Ravens when they won the Super Bowl in 2000 ... and even got himself an interception during the big game.