Find the ones NOT in costume...

[wholesomeisfine.]

There are many actual monsters lurking in this party...

Twist: If you find them all, you get a free pet on your WL!

[TheDarkLindsey]

error dog in bushes, orange/red monster dog only the head is showing on bottom left, red-eyed dog only showing head on bottom right, two candy corn creatures on the carved pumpkin pile, and one candy corn creature hanging out by the uncarved pumpkins, ghost draft horse looking out the window

[.egg.]

error dog in the leaves, ghost horse in window, demon dog at the bottom left, grey dog in the bottom right, candy corn creatures by the carved and uncarved pumpkins

[Alicat2632]

Bottom right, bottom left, glitch pps puppy in the bushes, ghost horse in the window, candy
Corns by both sets of pumpkins!