Giannis Antetokounmpo Made Big Purchase Before Big Contract

Here's Giannis Antetokounmpo buying a MASSIVE teddy bear at Costco ... just two days before he signed his big ol' $100 MILLION contract with the Milwaukee Bucks.

Don't worry ... it only runs about $30 ... so, he's gonna be fine.

We're guessing the Greek Freak was getting some birthday shopping done at the Milwaukee-area super store for his girlfriend ... whose birthday was also Saturday.

With that fat ass new contract, we're guessing there was some major jewelry that went along with that bear.