Hi Edmek! How are you doing?
The Ancient Danger creatures pack was a time-limited Itch release to celebrate the 6th anniversary of the Minifantasy collection. However, all the creatures in that asset pack (along with another 300+ add-ons and creatures requested by the community and created exclusively for Patreon) are available in the Minifantasy Patreon archive. You can access them by subscribing to the "2D Patreon Archive + Community" Patreon tier.
If you have any other questions, feel free to ask :)