Cockatrice, Basilisk's cousin. A creature feared just as the Timberwolves, maybe even more. I understand that the vision of being turned into stone and remaining like that for eternity isn't the most pleasant...

Stop right here. If all that worked as described above, don't you think that the Everfree would by now look like Canterlot Statue Garden? Better not mention the myth that some of those statues are ponies intentionally exposed to the curse of Cockatrice for preservation. Well, enough of gossip, let's focus on unraveling this mystery.

Cockatrices
Hierarchy

One rooster lives with his "harem" of three to four hens, at least in a medium-sized territory. The hens aren't in flock, they are just dispersed around the area, trying to fetch something edible on their own.

The only time they get nearer together is when another rooster challenges their "master" to a duel over his harem and position. The duel is basically just a "stare off", because cockatrices aren't completely immune to their own weapon. It is usually started by crowing in rival's territory. Sometimes one of the opponents--almost always the intruder--then changes his mind and doesn't want to reciprocate the stare, leading to a talon-sharp punishment from the indigenous rooster.

Roosters themselves have hierarchy that carries out thorough the whole Forest. Higher the position, larger the territory and more tolerated right to enter and cross other territories.

Diet

They primarily feast on insects, earthworms and slugs--after rain, their beak isn't shaped for digging--but don't mind berries and seeds either. Rarely do they spice their diet with smaller mammals or fallen hatchlings and eggs.

They never use the stare when hunting, otherwise they would die from hunger. Their bigger prey would be either scared off or turned to stone immediately. Which may seem good as a way of trapping since they have the ability to release their petrified victims on will, but it's really energy-consuming, more than what the small bird or mouse would be worth. And with the invertebrates, it would either cause nothing, which would again mean a needless loss of energy on staring, or create a little crunchier food.

Range

Territories are marked by crowing of roosters and pheromone secretions in hens' cases. They are more common in the parts of Forest with bushy undergrowth, closer to the centre of the Everfree, yet once or twice have I heard of them from the Forest borders.

They aren't really good fliers, they can hover just above the ground or glide short distances if they climbed up some tree before or tried jumping up.

Territorial behavior

Upon spotting a movement, their tactic is to crawl nearer, covered by surrounding bushes, then stick out a little their head in the opposite direction than the victim is to map the situation around by sideglances and hearing. This probably helps them to not misuse their stare. They usually try to pin down the possible danger with their talons to petrify or eat it. Bigger creatures always end up petrified. The only reason the Forest is not full of "possible dangers" turned to stone is that the petrification is temporary, and serves only as a lesson and further warning, much like the disgusting secretions of any slightly poisonous animal.

Except the marking and challenges iniciated by crowing, they communicate through infrasound waves, much like elephants or snakes. It might be surprising, but their sight isn't as good as you'd expect it.

Reproduction

From spring to the beginning of autumn, hens can lay up to two leathery eggs. Hatchlings are dependent on their mother, requesting food by staring and by pecking the red parts of mother's wings--much like many seagull species do with parents' beaks. They wander away after reaching maturity to join or fight for other territories.

Age: up to twenty years

Handling the petrification, appropriate behaviour

Petrification: small hammer should be more than enough. Or if you are afraid, the stone starts falling apart on its own after day or two. The trapped one is in the state of 'hibernation' during their stay, when you pull them out, they awake. Provide the victim with fresh water and something to eat and they should be fine. The stone is really just a crust on the surface. Let's say that testing this theory was quite... peculiar.

Also, some old sources say that the Alfa rooster's stare might cause something more durable and maybe even permanent, but I haven't collected any proof to that yet.

Another interesting fact is that the stone their prison is made of is the same as the nearest parent rock. I suspect they derive it at least partially from there.

Upon meeting them: fly/teleport/run or stay completely still--not sure which is better, especially for earth-bound ponies. You can close your eyes and wait, hoping that they'll think you aren't a living creature. If you wanted to look, you'd need special goggles. Looking into their eyes "bare-eyed" isn't the best idea, as you'll receive a shiny new coat or a nice deep scratch from their talons, but that's common knowledge.

They fear foxes, their chicken part getting on surface. But normal pony doesn't usually have one with them. And if they are really angry, fox wouldn't help anyway. Mirrors are the only way how to attract them. When staring they are blind and deaf to their surroundings, so you can try and knock them unconscious. Though they'd snap back to reality immediately after spotting your hoof in the reflection.

Since we were already discussing creatures able to "alter" one's appearance, let's now mention a plant with similar ability, albeit this one will most likely not turn you to stone.

Lilium noxia cupiunt
as called by the botanists of Classical era, now commonly known as Poison Joke, is one of the rarest plants of the Forest. A small, innocent-looking blue flower with the ability to alter the physical form of any creature, from vocal chords to bone density.

There are only a few sites where they grow in the Everfree, but when they do, they are very abundant. They create patches of dense, linked underbrush, most of the individuals being asexually reproduced clones of just a few individuals. The plants require medium humidity and don't react well to being completely overshadowed; you'll most likely find them around remains of paths to the Castle of the Two Sisters or former clearings, both providing enough light for these plants. This makes the Poison Joke an excellent paleobotany indicator.

Their magic is contained in the powder produced by anthers and also the outer membrane of their pollen, primarily emitted as a protection from herbivores and pollen eaters. Touching the plant carefully and in right places won't cause any harm--just like nettle can be held tenderly to prevent it from stinging. Poison Joke is pollinated by wind, but a few pollen grains touching your coat as they fly by don't seem to leave any effects.

By this time, you are probably wondering how is it possible that you have probably seen the blue flowers everytime you have ventured into the Forest. If you were lucky enough, these really were the rare Jokes, but much more likely it was the common Lilium hyacinthum, "Blue Archer" as called in old Zebrican. These plants don't mind being overshadowed by the treetops nor do they mind wetter soil, so that's why they are a typical plant of not just the Everfree Forest.

You can tell the Archer apart from Joke by the presence of white or light blue spots at the base and at ends of petals. Though the most accurate--and also the easiest--method is the number of stamens. Poison Joke has four, you can remember it by four letters of the trivial name, J-O-K-E, while archer has six of them, again a mnemonic device: A-R-C-H-E-R.

Also Joke is a hemiparasite, while the shadow-loving Archer is holoparasitic, but that's just a minor detail, not needed for survival. Any basic biology textbook holds the meaning of these two terms, should you seek further explanation.