Local Lycanthropes

Lycanthropes are a fun monster type and the usual types are well known. The RUS rpg had lycanthropy as a possibility for every character and a bunch of animals people don't usually think of. They were not obligated to be bloody killers but were persecuted. As a monster fan as a child, I had my Usebourne books with ere snakes, elephants and other lycanthropes. Actually, my favourite in dnd is the Devil Swine (Bronze Golems need more love in your dnd too). I like specialist clerics in my game who can turn lycanthropes and force them to change.

So there is just some tables of regional were creatures.
I have considered a goblinisation disease that protects you from other plagues.

These are just ideas though I would try and cover many if I did a monster book.

D12 Northern Woodlands
1 Wolf

2 Bear

3 Rat 

4 Boar/Swine

5 Badger

6 Elk

7 Owl

8 Horse

9 Raven

10 Fox

12 Lynx

D12 Tropical 
1 Tiger/Lion 

2 Panther/Jaguar

3 Jaguar

4 Ape

5 Hyena

6 Elephant

7 Crocodile

8 Jackal

9 Snake

10 Butterfly (nope not nice)

12 Scorpion

D12 Aquatic
1 Sea Wolf

2 Shark

3 Ray

4 Squid

5 Starfish

6 Eel

7 Lamprey

8 Crab

9 Walrus

10 Trilobite

12 Fish (various)

D12 Underland
1 Spider

2 Bat

3 Toad

4 Crayfish

5 Mole

6 Worm

7 Beetle

8 Lizard

9 Toadstool

10 Cricket

12 Fish (various)