Mullen's growls are considered to be the blueprint for modern death metal vocals. He is considered as one of the first in death metal to achieve a lower-pitched vocal style (often referred to as "death growls").
Mullen is also known for his frenetic "hand chops" at Suffocation concerts; and for his funny and sometimes bizarre stage banter.
Frank Mullen has a daughter named Rayna Mullen.
Also provided a guest vocal spot in the Suicide Silence song "Smashed".