The Orchard is basically a piece of the Feywild transposed onto our plane. The trees, food, even water there are different from here. Most things from there are ridiculously dangerous. At best, the apples are just poisonous. At worse, they'll enchant you and make you only able to eat more of them, deadening your senses to the mundane world and progressing the curse. Each apple only gets you closer to true enthrallment.
As with all things fey, everything in the Orchard is ridiculously deadly, but also dead ridiculous. The satyrs there will praise you for answering their riddles correctly and shower you with gifts one moment, then murder your friend and not understand why you're sad, or off-handedly doom you to a lifetime of colourblindness by feeding you the wrong apple as a prank. Don't trust anything there.
The pixies, brownies and quicklings of the place are deadly, and extremely prone to pranks. Expect your things to be messed with or go missing outright unless you pay very close attention during watches. They like to steal shoes.
There are more sinister creatures that live there, too. Dangerous beasts like owlbears that won't stop at your shoes and will take your foot outright, or deadly bands of shadows that are created by a yet undiscovered necromancer. There are also very old, years-old rumours of a woman named Eilsana who lives in the south of the orchard. Her upper body, a high elf sorceress, but below the waist, she's been gruesomely grafted to the body of a gigantic spider. She's said to miss tea, hate fey, and be willing to talk to those who don't threaten her children. The AAR of the group that met her: https://www.reddit.com/r/West_Marches/comments/6comjo/aar_do_spiders_read_road_signs_22_05_2017/
Two enigmatic figures of the Orchard are the Knights of Spring and Winter. They fight intruders, Eilsana and players alike, yet in very different ways. The Green Knight, or Knight of Spring, is a suit of armour that attached itself to a host forcefully, crushes their mind, and uses them as a vehicle to defend the Orchard. The Green Knight features in a huge number of stories about the Orchard; they've even had a poem written about them.
The current Green Knight is a Hobgoblin Knight named Vekla who's doing her best to reconcile the armour's curse and her loyalty to Zrog. In the past, a player named Hedda Nackle was the Green Knight before being saved. While under the armour's control she fought many groups of players, but also was helped by a group of players in fighting off an incursion of fire elementals that threatened to burn down the Orchard. After they helped her, she allowed them to leave unharmed as long as they promised to leave the Orchard as soon as possible.
The Green Knight has been seen riding a stag in more than one of their forms, and the stag occasionally leaves tiny green gemstones of little value in her footsteps.
The Knight of Winter is a much less well known figure, but he's said to have been outright charming and chivalrous with players while asking them to leave the Orchard. That doesn't mean he's not happy to fight them if needed, however.