From publisher blurb:
Issue #10: Monsters That Improve with Age 2
The age chart is a powerful tool for Mutant Lords who want to scale monster encounters with the powers and artifacts of the player characters. These charts describe how a creature’s characteristics change over its lifespan, using three columns: the age of the creature, its hit dice, and notes. Notes might include damage, mutations, drawbacks, or anything else that affects the creature in and out of combat.
Though the first Age Charts article (Wisdom from the Wastelands, issue #2) introduced the basic idea and structure, there are still plenty of other possibilities that go far beyond that starting point. This issue presents example charts for creatures that weaken during the last stages of life, giant creatures (kaiju), plants, and truly odd creatures that go through metamorphoses as they age.