Pharrell's Hat ON FIRE -- Smokey Bear Don't Care

It's the first time Smokey Bear's ever added fuel to a fire -- telling TMZ, he couldn't be more amped that Pharrell ripped off his famous hat last night at the Grammys ... which is more than we can say for Arby's.

If you didn't watch the Grammy Awards last night, you probably still saw Pharrell's insane Smokey Bear styled hat somewhere on the horizon ... and it caused a FIRESTORM on the Internet.

Obviously we didn't speak directly to Smokey Bear -- he's way too busy fighting fires -- but his rep tells us, they're ecstatic ... Pharrell's hat "is proof that Smokey is as relevant an icon today as he was 70 years ago."

Even Arby's got in on the action ... tweeting, "Hey @Pharrell, can we have our hat back?" Pharrell tweeted back, "Y'all tryna start a roast beef?"

Fun Fact: The U.S. Fire Service and The Ad Council created Smokey in 1944.

Only YOU can prevent fashion disasters.