Headless Horseman's Hearthstone
Source: World Event.
The 
Headless Horseman's Hearthstone is a Hallow's End toy that replaces your standard hearthstone with a spooky animation, available for 150 
Tricky Treats from a vendor in Elwynn Forest.
Guide awaiting review
Travel to Alliance Vendor
Head to Dorothy, a human kid vendor, at 62.2, 66.47 in Elwynn Forest. She sells the Headless Horseman's Hearthstone for 150 Tricky Treats.
Purchase the Hearthstone Toy
Buy the Headless Horseman's Hearthstone from Dorothy. You can also reference the secondary map point at 31.82, 50.1 in Elwynn Forest if needed for navigation.
Use and Enjoy the Toy
Add the toy to your action bar — it functions as a full hearthstone replacement, so you can discard or bank your 
Hearthstone. When used, it creates a circle of flames around you, places a 
Hallowed Helm on your head, and your character laughs upon completing the cast.
Tips
You can combine this toy into a mouse-button macro alongside the
Dalaran Hearthstone and 
Garrison Hearthstone to keep all hearthstone options on a single action bar slot, using left click, right click, and middle click to trigger each one.Other hearthstone toys such as
The Innkeeper's Daughter and 
Greatfather Winter's Hearthstone function identically as hearthstone replacements if you want alternatives. See the video guide for a full walkthrough.
