i think even as a child i recognized that the platypus is a gimmicky animal
The platypus doesn't even have a single gimmick, it has a load of them. (Most of these things are also true of echidnae, which are basically platypodes that got anteaterized.) Its stance, metabolism, and reproduction are halfway between reptiles and other mammals. It has milk glands, but no teats or nipples, so it just sweats milk through its skin. It has two uteri and a spiky asymmetrical forked penis (the penis of echidnae is four-headed). It completely lacks a stomach. It has five pairs of sex chromosomes. It can perceive electric currents in water through its fleshy bill. Males have a venomous stinger on their ankles. It's a mess.
echidnas being surprisingly good swimmers (because they used to be aquatic?) is a fun fact
depsidase