Holer resembles a spiked, orange cactus rising out of the ground. Holer's spines are much thicker than a traditional cactus. Though it's supposed to be a deity, like Uranos, it's not given much gravitas in the series. Though pure conjecture, it may simply be small parts of a larger being.
Although it is stated to be male, Horae are the goddesses of the seasons and the natural portions of time. It could also be inspired by Hegemone, the Greek goddess of plants and their ability to grow, blossom, and produce fruit.