They don't.
A "porky" is a lie. If someone has told you that Australians call echidnas porkies, they are telling you a porky.
Some people may call them porkies for two reasons - porkie is short for porcupine and, even though echidnas are not related to porcupines, they have sharp spines like porcupines do. Also, the word porcupine rhymes with spine (the sharp quills on an echidna) and Australians are fond of rhyming slang.
There's no collective term for a group of echidnas.
You call people living in Australia, Australians.
Australians call them "lifts", but the word "elevators" is not unknown.
Watermelon, Australians just have an accent.
they probably do but it might sound really soft that you can't even hear it to call other echidnas.
i presume you mean do Australians call us poms? if so yes
KIDS
it is a veranda
Tasmania is inhabited by humans (specifically, Australians) and a wide variety of wildlife, including Tasmanian devils, echidnas, platypuses, wallabies and more.
We call them thongs, and yes, many Australians wear them.
If it is an outdoors "grill", it is probably what Australians call a Barbeque. With increasing frequency, it is sometime known by its brand name as a Webber.
Australians commonly call chickens "chooks" (rhyming with looks).