WARNING: The following contains spoilers for So I’m a Spider, So What? Episode 3, “Earth Wyrm (Dragon), Bad News?” streaming now on Crunchyroll.
So I'm a Spider, So What? has been winning audiences over from day one with its self-aware nature, likable main character and unabashed enjoyment in turning the isekai genre into a story of survival of the fittest. Since the characters enter this fantasy realm from the "real" world, it makes sense the series is filled with real-world pop culture references, and Episode 3 goes particularly heavy on references both expected and unexpected.
The most predictable reference is, of course, to Marvel's premier web-slinger, none other than Spider-Man himself! When leveling up gives the unnamed spider heroine a chance to gain new skills, most notably Thread Control, she can't help but fantasize, decking herself out in the blue, red and black of "New York's favorite friendly neighbor." Not only is the scene complete with the spider heroine swinging around tall buildings with ease, but her love for Marvel's creation and absolute glee at the concept of being like the hero is clear in the voicework. It's almost impossible to work with actual spiders and not want to throw in a reference to Spider-Man somewhere.
Less predictable, however, was the episodes' second notable Easter egg. In a post-credits scene, once our spider has made good use of her new Thread Control skill to avoid certain death from fall damage, she ends up in the lower regions of the dungeon where she encounters many powerful monsters -- and three of the snakes that gave her so much trouble in the previous episode. Upon seeing them while being chased by wasps, she exclaims "I'm supposed to fight King Ghi--ra now?!"
Any Godzilla fan will immediately recognize this as a reference to King Ghidorah, one of the franchise's many kaiju, but the explicit reference only serves to highlight the more subtle one -- it's the combined appearance of the wasps and the snakes that together resemble the great monster. The wasps provide King Ghidorah's signature gold color and wings, while the three snakes refer back to its three dragon-like heads.
Given the series' focus on deep dungeons underground and powerful monsters, it seems appropriate that it would reference one of the most popular monster franchises in addition to the obvious-but-appreciated Spider-Man parody. Fans now know to be on the lookout for future pop-culture Easter eggs that should serve to further enjoyment of the anime.