The crocodile is gorgeous! Hope he/she has a long and happy life.
The Aigle suggestion is sound. They
can cost around £100, which is an awful lot for a pair of wellies - so look hard to find them at a discount (as suggested above) if you decide to go for them...they're designed on a walking boot 'last' and are probably the most comfortable welly boot you can buy. There are several styles, closures and designs - try them on before buying.
The only trouble with wellies is you might find they're not ideal if you start doing longer walks. If you find you're doing, say, five miles, then maybe proper walking boots would be more comfortable...and better for your feet!!
The number of makes and styles is bewildewring. You
can buy decent waterproof walking boots for around £75 - £85 but eventually you might find yourself going for even better boots if you go down that route... they say you get what you pay for and this can be very true of walking boots...unless you bag a bargain and get a good, known make at a good price...which is very possible. Most important is to go to a
proper outdoor shop to try them on. They often have knowledgeable young staff who tend to have a bit of an idea.... Sports Direct is not generally advised if you want advice - and DON'T BUY KARRIMOR BOOTS in Sports Direct unless you really know what you're looking for. In fact, to be on the safe, side avoid Sports Direct as a rule.
A reliable name in reasonably priced walking boots is Grisport.
http://www.grisport.co.uk/walking-boots-c78
The big names like Scarpa and Meindl are definitely dearer but definitely better than the cheaper ones you might find in Blacks or Milletts (although both of them do decent makes too).
Whatever you get you MUST treat them with waterproofing stuff like G Wax...even if you get fabric boots, still treat them! Trust me. Even if you get Goretex lined boots....still treat them!
You'll find lots of fabric boots and, increasingly, less full leather boots. Fabric waterproof boots with a waterproof liner (like Goretex or Sympatex) are usually comfortable straight out the box. Stiff leather boots (with or without a waterproof liner) are generally less comfortable out of the box and need breaking in...but once broken in are durable and strong.
I have a recommendation...but it's an expensive one_
Lowa Renegade Mid GTX
Both my wife and I have two or three pairs each...just in case they went out of production. Fabulous boots!!!!!!. Waterproof and comfortable out of the box...we both love them. The only problem is my wife now needs
extra wide boots due to bunion surgery - and she (and I) have each got a pair of Meindl Merans...and they are even more gorgeous!!!!!!!!!!!
https://www.hillanddaleoutdoors.co.uk/productDetail.php?productId=701&brand=9
You would need to shop around....AND TRY THEM ON FIRST!!!
There is another option... see here...
https://www.amazon.co.uk/Nokian-Foo...detail-softlines&pd_rd_r=W06YKSJFPS0HC8BGFP09
I have a, little used, pair but don't get on especially well with them - but I know a Dartmoor Guide who swears by them and walks for miles on Dartmoor in them (I only bought them on his recommendation). What size are you?? Mine are 43.
There really are lots of options (and I've tried most of them) and you'll learn by your mistakes unless you can get sorted early on.
Another name to look for in the wellie line is Buckbootz
https://www.bucklerboots.com/ I have their steel toe cap version of wellie boots and they are absolutely super...but not for walking five miles in. The non steel toecap version might be more suitable for you. But you must try them first.
The neoprene suggestion above is another sound one...I have tried several different makes, including Muckboots, but didn't really settle on them but lots of people love them. See somewhere like this....
https://www.wellywarehouse.co.uk/womens-wellies/warm-wellies/shopby/muck_boots
But you need to try them somewhere before buying them....or at least have a good returns procedure.
Brasher Boots used to be one of the big, reliable names...like Karrimor used to be. But both makes have been taken over (unsurprisingly) and Brashers aren't quite the stable, reliable name they once were...but, at the right price, they're still better than Karrimor. (I don't like Karrimor)
Have a scratch of the head and look around at the options and ask more questions if need be...but, honestly, you might not get it right first time.