Glyph of Shadowy Friends

This is one of the new glyphs that is learned from making the the Scroll of Wisdom as a scribe, using your daily cooldown. The skill difficulty is incomplete, as the glyphs can be learned as early as 525 (when you can make Scrolls of Wisdom). It will be orange and provide three skillups all the way up to 595. If you are going for realm first, crafting the first glyph you discover so that you hit 594 is the way to go, so you will hit 597, and then you can make 2 epic shoulder enchants and ding 600.

This glyph is now available from the daily research Scroll of Wisdom.

Here is a full list of the available glyphs:

Priest:
Glyph of Shadow Word: Death
Glyph of Vampiric Embrace
Glyph of Confession
Glyph of the Heavens
Glyph of Holy Ressurection
Glyph of Shadowy Friends
Glyph of the Val'kyr

Warrior:
Glyph of Incite
Glyph of Blazing Trail
Glyph of Burning Anger
Glyph of Crow Feast

Hunter:
Glyph of Black Ice
Glyph of Direction
Glyph of Marking

Paladin:
Glyph of Battle Healer
Glyph of Mass Exorcism
Glyph of Bladed Judgment
Glyph of Falling Avenger
Glyph of Focused Wrath
Glyph of Righteous Retreat

Druid:
Glyph of the Cheetah

Monk:
Glyph of Blackout Kick
Glyph of Breath of Fire
Glyph of Clash
Glyph of Enduring Healing Sphere
Glyph of Expel Harm
Glyph of Guard
Glyph of Honor
Glyph of Jab
Glyph of Mana Tea
Glyph of Rising Tiger Kick
Glyph of Spinning Fire Blossom
Glyph of Spirit Roll
Glyph of Transcendence
Glyph of Water Roll
Glyph of Zen Flight

Edit: And here's the monk part for you guys. It seems they still didn't link glyphs with the research.

[spell=126745], which will return the shadow effect on your Shadow Priest Mounts after 6.2.0 Build 19890, is obtained from

Glyph of Shadowy Friends, which is a MINOR glyph obtained from venerable content and requires the Inscription profession (Level 525), 1x Light Parchment and 3x Blackfallow Ink to craft.

Your Shadow Priest will need to be Level 25 in order to apply the glyph.

As stated in the item tooltip, your NON-Combat Pets will also be affected. (OBTW, if you'd like to know the difference between "affected" and "effected", please ask. There are many here on Wowhead whom will gladly assist you on such questions!)

Shadow Priest Hub Page: [http://www.wowhead.com/guides/classes/priest/shadow]