Migos, Diplo, & J Balvin Perform at $4 Million 18th Birthday

Migos, Ashanti, Ja Rule, J Balvin and Diplo ... could be a list of Grammy performers -- or just some of the performers and guests at an 18-year-old's $4 million birthday party in San Antonio.

The lucky guy is Thomas J. Henry Jr. -- son of the uber successful personal injury lawyer, who you might recall dropped $6 million on his daughter's quinceanera.

Jr.'s bash was anything but low budget -- DJ Ruckus spun all night with the all-star musical performances and celeb guests like Austin Mahone, Lance Bass, Joanna Krupa and Adrienne Bailon.

There was also a Cuban cigar roller, a bar completely made of ice.

So what do you get the kid with a $4 million party as a present? Eh, just a nice watch ... and a Ferrari.