Adrian Peterson Costume Hits Beverly Hills ... It Was Only a Matter of Time

You knew it would happen ... and last night in Hollywood we got THAT guy -- you know, the one who dressed up as Adrian Peterson for Halloween and whipped a toy baby with a switch.

It may seem a little over the line ... but you know every costume party this year is gonna have at least one person wearing the purple #28 jersey.

And besides, it's not like he dressed up as Ray Rice!

Oh wait ... someone already did that too.