Introduced in Dragon Quest IV, they are essentially a cross between a platypus and a monkey, the 'punk' in their names likely referencing their Mohawks.
Platypunks are short, round creatures with duckbills, bird-like claws, long, monkey-esque tails, and a Mohawk. They are often depicted as being white and silver furred and their eyes have a roundness to them that is similar to that seen in Slime eyes.
In terms of strength, Platypunks aren't too strong, often being one of the weakest enemies in the games they appear in. Their methods of attack have varied between spitting water, spinning out with their tails, or viciously scratching with their claws.
In the Slime MoriMori series they are established as the primary villains, though they still aren't very strong.
Platypunks reappear as monsters from the start of Version 4 onwards. Prior to their reappearance in the 2012 game, they appeared as prism while one appears as guide for the fishing minigame from the first half of 3.4 onwards.
Don't be fooled by their fluffy fur and funny faces—these big-beaked bad 'uns pack a punch! One whack from their long, white tails can set enemies snoring—and sometimes even bring about the Big Sleep.
Platypunk appears as a F-rank monster of the Beast family and can be recruited from Episodes 2 and 3 of Chapter 4. It can also be recruited from the Orc King Fortuneteller stage from The Beastliest Beast of Bravas Qualifiers during the limited Beast Fest event at any difficulty, as well as the Platypunk stage of Terry's Big Tour: Woodwin during the limited Dragon Quest Monsters: Terry's Wonderland 3D event at any difficulty. The platypunk can participate in Great sabrecub, Bewarewolf, Rashaverak, and Thunderbird's Battle Roads as a party member.