Namely, a creature that is immobile and stone(like) during the day and mobile at night. Something like the old cartoon, but they don't have to be sentient.

  • They don't have to be actual stone, just something like stone, and unable to move.
  • They don't have to fly either.
  • Other than humans, would they have any predators?

4 Answers 4


That kind of creature is possible. First to make them hard as stone their skin have to be evolved differently. When sun light hits their skin it should turn hard either due to evaporation of water content of skin or they get stored in other parts of body to avoid water loss. These kind of creature might evolve in areas where there extreme heat during day and suitable temperature during night. So these creatures might turn into stone like to survive in these conditions. Any birds or any other animals who can break their hard stone like skin during day or have digestive enzymes that dissolves hard rock like outer layer might be their predators (considering they can survive the extreme environment during day).

  • $\begingroup$ I like this idea. I was thinking it could involve heat, but wasn't sure how it would happen. $\endgroup$
    – AndyD273
    Commented Apr 26, 2015 at 18:06
  • $\begingroup$ I have also the same idea. However, if the creature remains in a dark place with few light, it won't change its skin. $\endgroup$
    – pys
    Commented Apr 26, 2015 at 18:14

The first thought that comes to mind for me isn't what the current answers have dictated. Why does the creature need to have some sort of skin that "changes" form?

First, the satisfy the day/night criteria, we can say that this creature has evolved to sleep during the day and not the night. Nocturnal, like bats.

Because the creature now sleeps in the daytime, we're automatically satisfying the immobility factor.

All that's left is how it turns "rock hard", which is simple.

Think "extendable armor plating". First, the theory: When you have 2 thick pieces of material like so:

|=====||=====| (where each |=====| section represents a plate)

The plates can't move back and forth. They're very sturdy as well. So how do we give this the ability to move? First, we have to modify the plates. I think having diagonal connection slots would do the trick. If there were a muscle under each plate that pushes it up slightly, and the creature had slight hunch (or a lot of curvature), it could look something like this:

\=====/ \=====/ \=====/ (where the \ and / represent the the sides of the plates)
   |       |       |    (each | represents a muscle in the extended position)

As you can see, in this setup, the armor plates are no longer touching while the muscles are extended, which means that they're effectively "mobile" plates. Now our creature has full mobility when needed, and when it needs to hunch over and go to sleep, pull all the muscles tight, and the plates fall into place perfectly, creating a seamless "shell".

These plates can be made of really thick skin, if you want, or even bone. With the right bone density, these things could be ridiculously tough to kill.


I don't think such a creature would be able to evolve naturaly. I can't think of any material that reacts to light by turning hard as stone. I see two possiblilities:

1: The creature sleeps during the day and doesn't move. But it would be able to move if you wake it, even during the day. You could say it's armour is so hard and thick that it doesn't feel anything, so it would be very hard to wake the creature.

2: You'd have to use magic.

Furthermore, seeing as they have an almost impervious armour there is probably another creature hunting them. Why else would they need their armour. And because the armour works best at daytime it is probably a predator that hunts in daytime. But I don't know what creature that could be, probably not a creature that we know.


I can think of two possible "realistic Gargoyles", the first is a Chiropteron, and the second an Artiodactyl, both evolved to live in mountains, cliffs, and any stony and elevated place. I will develop both ideas:

● Chiropterans: Their ancestors are Microchiropterans that, due to evolutionary pressure, developed hollow bones with an internal honeycomb structure and air bladders. Thanks to this adaptation, these bats can reach sizes comparable to that of the extinct Pterodactyloids. Within this group, we have the Gargoyles, which are omnivorous and live in mountains. Like many real bats, Gargoyles are nocturnal, sleeping during the day on mountain slopes, protected only by their thick fur. Their skins are warm and thanks to their dark gray color they easily absorb the sun's rays, turning them into heat, but apart from that, their color and rough texture make them look like stone, thus avoiding the attention of predators during sleeping hours. . In historical times, Gargoyles have been reported nesting in the towers of castles and churches. Being that they are social animals, it is not uncommon to see entire herds sleeping in mountains, pretending to be statues, or herds looking for food together.

● Artiodactyls: Let's imagine a cross between a Mountain Goat (Capra pyrenaica) and a Flying Dragon (Draco Volans). An animal that feeds on grass, lives in the mountains, and escapes from predators, or simply glides across the chasm with a pelagium that runs along modified ribs. As an extra, let's add hair fused in scales similar to those of a Pangolin, which serves both as protection, and for camouflage, by pretending to be stone. When they feel threatened, they crouch down and stay still, pretending to be part of the environment.


Se me ocurren dos posibles "Gargolas realistas", el primero es un Quiróptero, y el segundo un Artiodáctilo, ambos evolucionados para vivir en montañas, acantilados, y cualquier lugar pedregoso y elevado. Desarrollare ambas ideas:

●Quirópteros: Sus ancestros son Microquirópteros que por la presión evolutiva desarrollaron huesos huecos con una estructura interna de panal y vejigas aéreas. Gracias a esta adaptación, estos murciélagos pueden alcanzar tamaños comparables al de los extintos Pterodactiloideos. Dentro de este grupo, tenemos a las Gárgolas, que son omnívoras y viven en montañas. Al igual que muchos murciélagos reales, las Gárgolas son nocturnas, y duermen durante el día en las laderas de las montañas, protegidos únicamente por su gruesa piel. Sus pieles son abrigadas y gracias a su color gris oscuro absorben los rayos del Sol con facilidad, convirtiéndolos en calor, pero aparte, su color y textura rugosa los hace parecer de piedra, con lo cual evitan la atención de depredadores durante las horas de sueño. En época históricas, se ha reportado Gárgolas anidando en las torres de castillos e Iglesias. Siendo que son animales sociales, no es raro ver manadas enteras durmiendo en montañas, aparentando ser estatuas, o manadas buscando comida juntas.

●Artiodáctilos: Imaginemos una cruza entre una Cabra Montés (Capra pyrenaica) y un Dragón Volador (Draco Volans). Un animal que se alimenta de pasto, vive en la montaña, y escapa de sus depredadores, o simplemente cruza el abismo deslizándose con un pelagio que se extiende por unas costillas modificadas. Cómo un extra, agreguemos pelo fusionado en escamas similares a las de un Pangolin, que le sirve tanto de protección, como para el camuflaje, al simular ser piedra. Cuando se sienten amenazados, se agachan y se quedan quietos, aparentando ser parte del entorno.


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