This trinket has a chance to drop from destroying mushrooms.
If the Compass effect triggers while having the Treasure Map, the Compass effect is permanent for the remainder of the floor. (Other Mushroom effects will still apply in each room with their normal odds.)
By walking into and out of a room, Liberty Cap will change its effect.
This can be used to easily get the Compass effect.
This can be used to easily get the Magic Mushroom effect before Boss Rush or Dogma (as the Dogma boss room door will only close when touching the middle of the room).
Synergies
Golden Trinket / Mom's Box / multiple copies: One boost or copy increases the chance for activation to 50%, further copies to 100%.
This item quote is a reference to the Yoshi's Island level 1-7: "Touch Fuzzy Get Dizzy".
Psilocybe semilanceata, commonly known as "Liberty Cap", is widely present in nature and is a very powerful psychedelic mushroom which contains psilocybin.
The Liberty Cap's ability to grant the Compass effect was a bug in the original Binding of Isaac which was carried over due to popularity with the fans.
The pickup quote for the Chinese translation (一摸一起躺板板) is a reference to a popular meme [1]
If the Compass effect triggers while having the 
Treasure Map, the Compass effect is permanent for the remainder of the floor. (Other Mushroom effects will still apply in each room with their normal odds.)
Golden Trinket / 
Mom's Box / multiple copies: One boost or copy increases the chance for activation to 50%, further copies to 100%.
Mushrooms 
The Binding of Isaac: Rebirth
