What "just popped in there"?

The first Ghostbusters trailer was all about getting to know the new crew -- that would be Melissa McCarthy, Kristen Wiig, Kate McKinnon, Leslie Jones and their hunky secretary, Chris Hemsworth -- but this latest preview is heavy on the bustin'. Plus, there's a seriously cool cameo included.

Did you spot him?

EXCLUSIVE: Paul Feig Says There Won't Be Any 'Dress Shopping Montages' in 'Ghostbusters' Reboot

There's still no sign of Bill Murray, Dan Aykroyd, Ernie Hudson, Sigourney Weaver or any of the other O.G. cast members set to return, but there are a few other cameos of note. And we don't mean Al Roker. These cameos are of the supernatural variety.

Though we spotted him in the first trailer, we get a better look at Slimer being Slimer-y as ever.

More excitingly, the Stay Puft Marshmallow Man makes a brief appearance! Though, this time he does not look like something you love from your childhood that could never possibly destroy you...

Ghostbusters hits theaters on July 15.

ET visited the movie's set, where McCarthy and the rest of the cast teased more secret cameos, intense stunts and revealed exactly what's in that green slime. (Hint: There's tapioca involved.)

Find out more in the video below.