Raf compares fitting a grenade inside Laserbeak, who is usually kept inside Soundwave, to a turducken. A turducken is a dish consisting of a deboned chicken stuffed into a deboned duck, which itself is stuffed into a deboned turkey (Turducken - "tur"-"duck"-"ken" - turkey, duck and chicken).
This is the first time that Soundwave's drone Laserbeak is named onscreen; before the designation was only provided by the show producers.