a group of platypus is called a 'businesss'
unfortunately, you misspelled platypus. it is a common mistake though. more than one platypus are platypi.
The platypus's family group is Ornithorhynchidae.
The mammal group to which the platypus belong is monotremata.There are only two animals in that group: the platypus and the echidna, and they are known as monotremes.
The platypus is a mammal, specifically a monotreme.
Monotremes
You're thinking of the platypus, which lays eggs and can eject venom. But the platypus isn't a marsupial. No marsupial lays eggs or is venomous. The platypus is part of a small group called the Monotremes.
The platypus should not be called anything else. It is just a platypus. It is not a duckbilled platypus, or any other such misnomer.
The sub-group of mammals which lay eggs are called monotremes.This group includes the platypus and the two species of echidna.
The platypus is classified as a mammal. It has all the defining characteristics of a mammal, including the ability to nurture its young on mothers' milk. It is a monotreme, of the order monotremata, meaning it is an egg-laying mammal.
From the time a platypus is hatched, it is called a platypus. It makes no difference whether the platypus is a day old, 17 weeks old or a year old. It is still a platypus. There is no official name for a young platypus. Despite what many websites report, a young platypus is not called a puggle.
The platypus is called the platypus wherever one happens to be in Australia.