There is a harmless, meme-based answer here. If you literally meant (the crop), then the “Top Unblocked Corn Hub” is a fantastic resource called The Maize Kernel or National Corn Growers Association —but those aren't blocked by schools.
The term "corn" is frequently used on social media platforms like TikTok and YouTube to bypass algorithmic censorship of adult keywords. Understanding the Keyword "Unblocked Corn Hub Top" unblocked corn hub top