The GWAR symbol is the Female symbol in pink with teeth drawn in the top loop.
A woman with a t-shirt with that symbol participated in the 1977 riots against the Costumed adventurers and called The Comedian a rapist. The symbol appears in graffiti along with the slogan "Castrate all rapists". They organized a Benefit Concert featuring Pink Triangle.
The toothed loop may be seen as a Vagina Dentata symbol, and gruesomely mirrors the mouth of the Alien Monster.