Mimics are just the worst in Dark Souls III. So, role-playing as one during invasions is a fantastic way to have some fun and troll invaders.
The rules are simple:
After dressing up as a Mimic (more or less), wait patiently guarding loot. If the invader approaches and takes the item or attacks, you have to attack as well and kill them. If the invader uses an Undead Hunter Charm, an item that puts Mimics to sleep, you have to lie down as well and the battle is avoided.
As JellyElite's clip shows, not many players had an Undead Hunter Charm, or were aware of its effects: