A pink godzilla is a woman who has had her heart broken by her ex, so for retaliation she then hits on all his best guy friends taking it as far as they are willing to go. She then feels like she "got him back" and feels like the heart break is over.
MAN: yo your ex just tried to get with me last night.
Man2: yeah me too.
Man3: well im glad i broke up with that hoe, shes a pink godzilla