Matt Ox -- the former child rapper hailing from Philly who got a huge look from the late XXXTENTACION at the age of 14 -- is older now, but staring down a potentially troubled future ... after he and his boys were arrested for drugs!!! Burbank Police tell TMZ Hip Hop that Matt was in the back seat…

Here's rap star Lil Uzi Vert proving his luv really is rage ... by beating the trash out of some dude in a private boxing sesh. It was reported the dude is 12-year-old rap prodigy Matt Ox, but his rep says it ain't him. No word on who the punchee is ... but he needs to learn to fight better.