In the episode “Artist Unknown,” the figures Spongebob carves out and Squidward accidentally creates are an obvious allusion to Michelangelo’s David.
Michelangelo’s influence is further evident in Squidward’s wise advice: Visualize the sculpture within. The words seem to be an echo of Michelangelo’s self-described process of “liberating the figure imprisoned in the marble.”
Da Vinci’s Vitruvian Man also makes an appearance in the background.
The Persistence of the Krusty Krab