Harry Potter Theory - Matters that were unexplained

What were the creatures in the Magical Menagerie?

In Harry Potter and the Prisoner of Azkaban Ron Weasley goes to a magical menagerie to get medicine for his rat. In this scene there are many different creatures are described. The creatures mentioned in the magical menagerie were never named as to what species they were.

"... a gigantic tortoise with a jewel encrusted shell was glittering in the window, poisonous orange snails were oozing down the side of their glass tank... Then there were cats of every colour... a basket of custard coloured furballs that were humming loudly..." - Section of Harry Potter and the Prisoner of Azkaban, Chapter four: The Leaky Cauldron

So first of all, the tortoise. I believe this creature is a Fire Crab. Newt Scamander (Author of the textbook Fantastic Beasts and Where to Find Them) states that "Despite it's name, the Fire Crab greatly resembles a large tortoise with a heavily jewelled shell..." which matches the description given in Harry Potter. It is also stated in Fantastic Beasts that Fire Crabs can not just be bought by anyone as they require a license as the creatures themselves can be dangerous due to their defense mechanism of shooting flames from their rear end.

Next on the list, the snails. Due to the mention of their poisonous nature I believe that these are Streelers. Streelers are described by Newt Scamander as having a trail so poisonous that it will burn all the vegetation it touches. They can change colour every hour which is why some wizards are inclined to keep them as pets. However these may be one to keep away from the kids.

Cats of every colour... I don't think all of these cats were your typical day to day cats, I believe at least some of these cats were Kneazles which resemble cats with outsized ears and a lion's tail. Since Kneazles can interbreed with cats some of the cats may be half Kneazle. I suspect this is what Hermione's cat Crookshanks is as he was a very intelligent feline able to detect deception quite alike the Kneazle. The Kneazle is also very loyal to a witch or wizard when it takes a liking to them.

Custard coloured furballs which hum loudly... no they aren't furbies in disguise. It's very likely that they are Puffskiens which are very cuddly furballs who hum loudly when contented. Fred and George Weasley breed miniature Puffskiens called Pigmy Puffs which are very alike the Puffskiens.

Authors Note: I always wondered what creatures were in the magical menagerie so I hope this helped any readers curious of any of the creatures.
If you'd like me to do more theories or noticed any unclear points in the Harry Potter movies or books please let me know and I'd be happy to do my best to analyse it and get an answer.