The Drop the Mic battle between Kunal Nayyar and Mayim Bialik has the following line from Mayim Bialik:
You're basically our show's Screech.
The battle between Ashton Kutcher and Sean Combs has a similar line referring to Screech, so this seems to be a somewhat common reference.
I don't get it though. Looking online, it seems that it might be a reference to Samuel Powers from Saved by the Bell. Is this correct? What is the nature of the Samuel Powers' character that would explain the line?