Your Constitution score increases by two, and one ability score of your choice increases by 1.

Your mushroom body is naturally resilient to physical harm, and by reactively flexing fibers you can turn away blows that would otherwise tear a chunk out of you.  As you become heartier, you become further able to shrug off harm with your esoteric biology.  When you take physical damage, you can use your reaction roll a d4. Add your constitution modifier to the number rolled, and reduce the damage you take by an amount equal to that total (minimum of 0 damage). This die increases to 2d4 at 4th level and 4d4 at 10th level. You can use this effect a number of times equal to your Constitution modifier + proficiency bonus.

Spores extend anywhere you choose within a 10-foot sphere. These spores can go around corners and affect only creatures with an Intelligence of 2 or higher that aren’t undead, constructs, or elementals. Affected creatures must make a DC8 Constitution save, which they may choose to fail, or become infected by the spore.  Affected creatures can communicate telepathically with you while they are within 100 feet of you. The effect lasts for 1 hour if uninfected, or indefinitely until the infection is cured.