Losing my edge: 'Battle Fungale' evades all my art-nerd credibility

Update: The Woot-ers have sent word that the T-shirt is now back in stock via this link, which is nice! But we're still left scrambling for the inspirational sculpture, despite Ridl's best efforts.

Though obviously -- because it's not 15 minutes after the T-shirt was first posted -- today's Woot shirt is long since sold out, Joel Drakxxx Rose's 'Battle Fungale' is still a nicely baroque homage to the Mushroom Kingdom, but something deeper's been troubling me. Despite the years of art history education for which I'm still paying the piper, I can't at all place what the image is a tribute to -- surely I'm mentally misplacing some lost European statuary?

Previously:
Imperial Junkie & Kiser: pixel fashionistas - Offworld
Polygraph's Kakuna T-shirt casts harden - Offworld
A new Hanes Beefy-T awaits - Offworld
Screaming for Hitekkai: Meat Bun's new T-shirt designs - Offworld
Louis & Bill & Zoey & Francis: the real fab four - Offworld