Perry posted an Instagram video of her latest hair transformation with pro Jesus Guerrero Katy Perry is the latest star to hop on the bob bandwagon ... to test run the hairstyle with a wig ...

The bob brigade is in strong formation ... Perry shared that the haircut is in fact a wig (but good luck to you if you try to google "Katy Perry wig American Idol," if you know what I'm saying).

having just digitally witnessed Katy Perry chop her long black lengths into a deliciously choppy layered short haircut. Combining both the shaggy wolf cut trend and the bob takeover, we give you ...

Katy Perry, 32, looked fabulous ... a gorgeous sparkly bronze dress that fit her to perfection, but her blonde bob truly stole the show.

Read more: Ryan Seacrest lifts lid on Katy Perry's American idol replacementLink In her initial Instagram post where she debuted the look, a shaggy bob, fans quickly commented and warned her they ...