Grim's Trunk, which contains all of Grim's objects, most of which are Supernatural, is a recurring plot device in the series. Many episodes plots revolve around something Billy dug out of Grim's trunk despite being told not to.
It's appearance varies by episode. In some episodes it is normal looking, but with a glowing aura or green. In others it is covered in skulls and various symbols.
In Billy and Mandy vs. the Martians, it's revealed that there is a large portal on the inside, explaining the large number of contents.
|Spider Egg||The Crawling Niceness|
|Evil Powder||Brown Evil|
|Voodoo dolls of Billy and Mandy||Brown Evil|
|Fancy Jake||Billy and Mandy vs. the Martians|
|Phone of Cthulu||Prank Call of Cthulu|
|Merlins Underwear||Billy and Mandy vs. the Martians|
|Holy Grail||Billy and Mandy vs. the Martians|
|Monster Manual Volume 1|