Updated to version 1.11: Planet Zoo: Twilight Pack.

The DLC includes Halloween items and crepuscular animals: a raccoon, a bear wombat, a striped skunk, a red fox and a display bat, the Nile fruit bat.

Planet Zoo: DLC Unlocker.

Unlocker DLC for Planet Zoo includes:

Deluxe Edition Extras

Deluxe Edition Animals

Planet Zoo: Arctic Pack

Planet Zoo: South America Pack

Planet Zoo: Australia Pack

Planet Zoo: Aquatic Pack

Planet Zoo: Southeast Asia Animal Pack

Planet Zoo: Africa Pack

Planet Zoo: Europe Pack

Planet Zoo: North America Animal Pack

Planet Zoo: Wetlands Animal Pack

Planet Zoo: Conservation Pack

Planet Zoo: Twilight Pack

Installation:

- Update the licensed version of the game on Steam to the latest version

- Download the archive

- Unpack the archive into the root folder of the game (Game Properties -> Local Files -> View Local Files), confirming the replacement of files

The game will now display parks, items, and animals from the DLC.

Unfortunately, the franchise requires purchased DLC as it operates online.