Chart star Chip joined a dream team of rappers - alive and dead - as they flew in from the US.
It's thought to be the first time the quartet have appeared on one stage. Tupac was shot dead in 1996, while his rival BIG died the following year.
Chip, who was known until last year as Chipmunk, performed a specially-composed rap as he lined up with the hip-hop heroes at Tussauds. Fans are invited to add to his tune online.
The wax figures have been brought together from attractions around the US.