what's poppin' fresh? 

This is a greeting meant to say what's up, what's crackin', or another such colloquial greeting. The reason it is popular is because Poppin' Fresh is the Pillsbury Doughboy's former name (the name was changed to update little Freshy's character and bring him into modern times). The phrase is not questioning what Poppin' Fresh is, rather it is using poppin' in it's slang meaning, and it is using fresh as a noun, not an adjective. Fresh refers to the person being addressed by the question.

Bob: Yo
Joe: Yo, what's poppin' fresh?
Bob: Not much kid, what's crackalackin'

what's poppin' fresh? by Marley September 2, 2008

what's poppin b

Commonly used as a greeting/text. Can be extremely cringey at times, however if it used ironically, it's ok. 'B' is short for, 'Babe', 'Bae', 'BB' and so on.

Boy: Hey, what's poppin b? X

Girl: Um, your a bit fucking weird.

what's poppin b by What's good my dood March 1, 2017

What's poppin 

To say hello to somebody while also asking what's new

Friend 1: Yo Vincent!!! What's poppin??!!
Friend 2: Not much man, but I'm starving. Hey wanna get some chipotle?

What's poppin by Trixrabbit24 June 26, 2016

yo yo yo whats pappin'

When someone is on Crack and trying to say "yo yo yo what poppin'."

Yo crack h*e get yo head ass sayin' Yo yo yo whats pappin'.

yo yo yo whats pappin' by Bring that Azz here boiii February 20, 2019

What's poppin, what's Gucci? 

It typically means "what's up" or "how are you doing" or "how's your day?

Friend: Hi Steph, What's poppin, what's Gucci?

Stephanie: Hey!!! Nothing much wbu?

What's poppin, what's Gucci? by Hi Shisters James Charles here July 3, 2018

what's poppin 

Short slang for, "What the fuck is going on, nicca?"

What's poppin, g?

what's poppin by Nuckra April 27, 2004

Whats popping 

When your trying to see what's good for the day / night.

Yooo, Whats popping my dude?

Whats popping by buttab September 21, 2006