I keep being reminded of those "Untoon" things. This wasn't as creepy, but it was still creepy. It truly does seem realistic. The point that really stands out is Mermaid Man's belt. I can see the wrinkles on their face! Mermaid Man looks a lot like Leslie Nielsen in this.
This is some of the best SpongeBob fanart I've ever seen. I love their expressions. I love how you got every single detail down just right. Heck, I just love this thing in general! A pity these guys weren't in the recent movie. Even the background is flawless!