This Underground is even emptier than Axetale’s. Blood and dust stain the walls, trees and ground permanently. The corpses of headless monsters litter the Ruins and the forests of Snowdin and hang from posts like grotesque scarecrows, eaten down to the bone. A fell wind, tinged with fear and iron, blows through the empty caverns, and through the land of winter and death walks the Executioner, the Head Collector, a mad skeleton monster wielding an axe so large it looks impossible to lift, its haft a strangely long and spiked spine.
The monster is out of his mind, and behaves much like a dog, sniffing at the wind and watching the scenery attentively as he walks. Attached to his chest is a broken, dirty baby doll in a baby carrier, and glowing in his shattered skull floats a fluttering crimson orb, always watchful and flickering and cruel.
If you are fortunate, he will not find you, though his sense of smell is incredible. If he does not find you, and believes himself alone and without foe, he will lift a small personage down from a basket slung across his back. She appears to be human, is dressed in frills and bows and treated with immense care, and calls the beast “daddy”. She is the cleanest, purest thing left in the Underground, and the skeletal monster would do anything to protect her.
Aliza fell into this Underground as a ten-year-old, a runaway from her grandmother’s "care". She followed the path of a scarlet butterfly, led to the mountain with whispered promises of happiness and a family she had never known, and found her last remaining family there, bringing a light and hope to Sans the skeleton that he had begun, even in his madness, to believe was completely lost.
Many of the monsters in Axefell have perished. Of the 12,000 that used to exist, only 100 remain. Flowey rules over the capitol, glutted on prey and high on power and madness. Napstablook haunts the Ruins yet, as untouched by the Hunger as he is in Axetale. Sans remains alone in Snowdin, clinging to the sanity that his "wife" (a mannequin wearing a wig) and "child" (a broken porcelain doll he found in the dump, along with the mannequin) give him. The Riverperson rows the swift, dust choked river, Onion-san hunts the swamps of Waterfall, and a few scattered Temmies bleat for food, alone and lost in the darkness. The Amalgams patrol Hotland, Mettaton the Core, while the remaining of the lesser monsters hide as best they can, hoping not to fall prey to the few, extremely powerful greater monsters. Gaster watches over this Underground reluctantly, cynical and unable to interfere. All others have fallen, meat for the Hunger of those that remain.
For the first time in a long while, true starvation, unlike the false and mentally-induced one of the Glitch, may very well be a problem. Once this sets in, the underground may very well go empty, and monsterkind will be sentenced to extinction.