The Shire Wolves are fairly easy to find, they 122 life, there is one special wolf called the Grim Maw which you can find in the Den, you get a trophy upon looting the corpse. Wolves give about 12 xp Deer, Conies, Foxes, and Red squirrels all have one life so one attack will kill them, they don't give xp though Biting Shrews, Burrowing Shrews, and Thieving Shrews all have 60-70 life so are good targets, they give 6 xp. Wild hill toads are found in the Frogmoors in great quantities and have around 170 life and give about 15 xp. Angry and wild tuskers are boars with similar life to that of Wild hill toads, they can be frequently found in fields along with wolves, they give about 12 xp. Harvest flies and marsh flies are giant lacewings with around 177 life and can easily surprise you when your swimming along the river. There is a deed that you unlock at about level 12, which is that you have to kill 30 harvest flies and then you get some turbine points and the title (your name), savior of the crop! Sometimes you can find bears and Goblin scouts between Scary and Overhill Bog Slugs are giant slugs which can be found in the Rushock bog and also in the area around farmer Maggot's farm Stinging and Buzzing Gnats are also commonly found in most bogs and have about 63 life, you also sometimes get them in fields. They give about 6xp. There are giant spiders in the Quarry at Scary, there is also a quest in which you have to kill so many of each. I do not recommend killing any amount of spiders in quick succession until your level is around 15 as they deal quite a lot of damage and also have a poisonous bite (this doesn't kill you by the way). Just south down the road from Scary you can find bats, they are level 11, but die surprisingly quick. Broadtooths are like tuskers, with around 122 life you can find them around Overhill, the logger village.
By the time you get to about level 10 wolves aren't a problem!