Your aptitude for Dexterity has heightened, you gain the following benefits:

• Crawling, moving through another creature’s space, and squeezing through a tight space doesn't cost you extra movement. In addition, as long as your not wearing heavy armor, squeezing through a tight space does not impose disadvantage on your attack rolls and Dexterity saving throws. 
• You have 2 reactions per turn instead of 1.