WTF! This is such random behavior, especially considering the fact that Travis is usually such a friendly guy...

The drummer was in Calabasas with his daughter Alabama when, out of nowhere, started hurling obscenities - and spit - at an X17 photog!

Travis threatened: "I'll kick the sh*t out of you, bro! If I didn't have my little girl in my hands, you'd be f***ed."

Whoa! In front of your kid, Travis? Not cool. What could've made the dude so mad?

Meanwhile, one of Travis' pals slashed a photog's tire - the police were called and a police report was filed. Our photog has this to say:

    "We've never seen Travis like this. He's usually so nice! All I said to him was 'hi' and he went off. I didn't even know how to react!"

Damn. Watch the craziness above!