GWAR Singer Vulvatron -- Fired Over Booze ... But Swears, 'I'm No Drunk!'

A GWAR of gwords is going down between the metal band and its fired singer Vulvatron -- they say she's a reckless drunk, but she says she totally parties responsibly.

Last week on Facebook, GWAR's Brent Purgason put Kim Dylla -- Vulvatron's not her Christian name -- on full blast for getting obliterated before shows. Although the band's official release was more PC ... Purgason's post claimed booze was affecting Kim's performance.

Kim tells TMZ ... yes, she'd typically have a few beers before a concert, but denies getting wasted. More importantly, she points out the band wears ridiculous outfits and sings about sex, drugs and worldwide destruction -- so guzzling a few beers should NOT be a big deal.

But she says what really chaps her ass is the fact GWAR is looking to hire a new singer to slip into her fake blood spurting boobs. She's upset because she created the character, but unfortunately GWAR owns it.

Silver living for the ex-Vulva -- she's pretty cute minus the bleeding rack!