‘platypus’ cases meaning

[Tedwonny]

Original Sentence:
There may be some ‘platypus’ cases that don’t fit neatly into these categories. Please let me know if you have any such cases. Let’s handle them one by one.

I know platypus is an animal and the writer use scare quotes to signify the special use of the word here but I am not familiar with the animal enough to decode the meaning from the context. Any ideas? Thanks

 

[SoothingDave]

The platypus is an animal that has fur and feeds its young with milk. So it's like a mammal. But its young hatch from eggs that the platypus lays. Like a bird or reptile.

It is thus the perfect example of something that is hard to categorize.

 

[Skrej]

It can also defend itself with poisonous venom, which is rare for a mammal but common in reptiles. Even though they nurse their young, they don't actually have teats, and instead secrete the milk through skin pores.

A very contradictory animal indeed.