-0.3 Speed. Isaac builds speed while in a room with enemies. At max speed, he gains the My Little Unicorn effect for 5 seconds.
Quote
"Speed down + rage is building"
Effects
-0.3 speed and maximum speed down.
When in a room with enemies, Isaac gradually gains speed at a rate of +0.065 per tick. This speed boost will be able to go past the lowered maximum.
Once Isaac's speed reaches 2.0, he gains the My Little Unicorn effect for 5 seconds, becoming invulnerable, and loses the speed bonus from Taurus afterward.
Synergies
The Virus - Isaac will poison enemies in addition to dealing damage to them on contact.
Serpent's Kiss - Isaac will poison enemies in addition to dealing damage to them on contact.
Gnawed Leaf - Isaac's speed will still increase while he is invincible from Gnawed Leaf, allowing Taurus to activate with only a very small period of vulnerability when first entering a room.