Also known as Fourth Transformation, it is a form exclusive to the Frieza Clan, first appearing in Dragon Ball Z Movie: Cooler's Revenge.
Unlike the previous three forms of the Frieza Clan (which suppresses the power of their real form a.k.a. Fourth or Final Form), the Fifth Form is a power up form similar to the Super Saiyan and Golden Frieza forms.
Its body changes include a growth in height, gaining spike protrusions and additional gem-like parts, natural red eyes becoming fully colored and pupil-less, and the inclusion of a mouth mask.
Cooler is the first and only one so far who is known to possess this transformation.