Ripley's Believe It or Not!: Bounty On 2 Heads ... and a DiMaggio Bat

The Ripley's Believe It or Not! museum in NYC is baffled over the recent theft of 2 shrunken heads and a Joe DiMaggio bat -- and now it's offering up a cash reward to catch the crooks.

The bat was from the Yankee great's historic 56-game hitting streak -- and the heads are from an Amazon tribe, which was probably on a streak too. Employees noticed the items were gone Wednesday, and police have no leads right now, but they're not ruling out an inside job.

Ripley's tells us there's now a $2,000 reward for any info leading to an arrest and conviction.

The mini skulls -- worth, believe it or not, $19,000 and $15,000 -- will be replaced by other shrunken heads. We're told they have plenty in storage. Not the case for Joe D's bat ... that's irreplaceable.

For now, Ripley's is replacing it with an autographed Michael Jordan bat from his time with the Birmingham Barons. Maybe the first time MJ is actually a downgrade.