First off, a little background. This is inspired by the podcast Welcome to Night Vale.
In a forest, a portal opened up to let out several paranormal creatures. After a year of spreading out, they went into aggressive mode. Several hundred people died. The first creature that was discovered was a large wolf with extreme speed and strength.
A few facts about this portal;
It produces a very low amount of radiation.
It must be in a forest (or someplace that can hide a portal).
It must be in North America (Canada or America).
This is in modern-day (no Covid).
It has a bright black color.
It has a low-frequency vibration.
It is about 6ft high and 5 ft long
Facts about the creature:
The creatures don't need food, sleep, air, or water.
They are tough to kill (just strong enough that they will just barely survive a drop from space (62 miles)).
Each has special abilities.
When they die, they disappear.
So, where is the best place for this to open up and not be discovered?
If you have any questions, please ask. I will answer it. I can provide some information about the creatures if asked (there's more than one kind of monster).