Archived Kimimaru4000 video from YouTube. Original description mostly intact:

This video showcases what happens in Paper Mario: The Thousand Year Door if you attempt to enter a battle with a Battle ID that doesn't exist in a particular location.

Enemies in the field are assigned a Battle ID that defines which enemies you encounter when you get in a battle. All areas in the game, except the Glitz Pit, share the same Battle IDs; however, encounters differ based on the area you're in. For example, although Boggly Woods and Petal Meadows both have a Battle ID of 00 defined, you cannot touch a Cleft in Boggly Woods and have it direct you to a battle against Goombas.

In this video, I set all encounters to lead me to Battle ID 08. Since the highest Battle ID Boggly Woods uses is 07, this is out of its range of possible encounters. Interestingly, instead of crashing or freezing, you instead see this behavior where it simply doesn't get you into a battle.

Thanks for watching, and enjoy!