Female Wieder Spinnetods (Grimm) experience the effects of rapid aging since they are unable to molt without consuming human entrails. Charlotte, who's actually 26 years old appears 70 due to her choice to not partake in the tradition of eating entrails.
Jack (Bioshock) grew up into adult at age 4.
Due to planned genetic changes in his creation, Solid Snake (Metal Gear) was designed to rapidly age, appearing to be a man in his 80s despite actually being in his early 40s.
Solidus Snake (Metal Gear Solid 2: Sons of Liberty) appeared more aged than the other two clones in his later life at age 37.
Martin Brundle (The Fly II), though chronologically five years old, has the body of a 20-year-old man.
As a Silpelit Diclonius, Nana (Elfen Lied) ages twice as fast as an ordinary human, appearing to be in her early-to-mid teens while actually being only six or seven.
Piccolo (Dragon Ball) became a full-grown adult in three years.
Upon birth, Adria (Stargate SG-1) aged rapidly until she was a grown woman within days.
Hiro-Kala (Marvel Comics)
Iris West II/Impulse (DC Comics) as a child...
... and an adult.
Jenny Quantum (Wildstorm/DC Comics)
As an E-type B.O.W., Eveline (Resident Evil) rapidly ages unless she is regularly given a special treatment to counter it.
Supers like Chloe (The Thundermans) and her older sister Phoebe have the fastest growth spurt in their family, despite their age when they are babies.
Adam Warlock (Guardians of the Galaxy TV series) became an adult in a matter of days
The Slave Army of the Republic - The Brutal Life of Clones -Legends- - Star Wars Explained
Clone Troopers (Star Wars) were made to have very fast growth spurt so they couldn't spent a lifetime growing up.