A fundamental constant is one that has to be measured by experiment, rather than being derived from any other quantities. Which values we choose to make fundamental and which ones are derived are somewhat arbitrary.
Koalas are native to southeastern and eastern Australia, living in forests of eucalyptus trees. They are basically sedentary animals that need to sleep a lot to give them time to digest their food. Being on the ground all the time would be a disadvantage, because predators could catch them easily.
Koalas' length differs according to whether they are from the southern part of Australia or the north. Koalas in northern parts of Australia are smaller, with males growing to a length of 74 cm and females growing to 72 cm. Southern koalas are larger. The males can grow to 82 cm whilst females can grow to a length of 73 cm.