Accelerate Creature Growth

Upon casting this spell, the caster manipulates time with respect to a creature. A creature ages up to two months per level of the spell. The amount of ageing must be decided before the spell is cast. Ageing occurs at a rate of one month per turn. The creature must make a constitution throw vs your spell DC or gain two levels of exhaustion. Any actions or movement the creature takes during the process occur is at half its normal ability (loses half its attacks, move base is halved, and so on). 

The material component necessary for this spell is a piece of bio-matter from the type of creature to be affected. If the caster touches the creature during the spell, no material component is required. The reverse of this spell, reverse creature growth, reduces the age of the affected creature by up to one month per spells level to a minimum age of one month. The amount of change must be decided before the spell is cast, and the reversal occurs at a rate of one month every two turns. The rules for the material component are the same.