Acore is the oldest tree in Whispy Woods Forest, and is around 800 years old. He is a close friend to Whispy Woods and has earned his respect and gratitude by housing many little woodland creatures in his roots and branches. The animals include Rick, Coo, Nruff, among many others. The animals he lends his body to have protected him for the many years that he has been alive. During a big storm, all of the animals (with the help of Tiff and Tuff) help anchor Acore down to the ground and stop him from being uprooted. Thanks to the efforts of them all, Acore survives the storm. Acore reveals that he was sound asleep during the whole thing, but still thanks them all for saving him.
His name is likely derived from acorn. The fact that he is a sentient tree is inspired by Whispy Woods, another living, talking tree in the series and whom Acore is acquainted to.