Thank you very much, トラセルsan! かっぱ seems to be a brilliant idea to start with Japanese
"vampire" in Japanese can be 吸血鬼(きゅうけつき/kyuuketsuki) or ヴァンパイア (vanpaia or banpaia).
As to manga with imaginary creatures, how about very famous ゲゲゲの鬼太郎 (ge ge ge no kitarou)?
Very Japanese, very famous and very interesting in many ways, for sure!
If you want to search on internet, recommended key words are also;
幽霊 (ゆうれい) = ghost
妖怪 (ようかい) = specter
お化け (おばけ) (almost same as 幽霊)
化け物 (ばけもの) (like spooky creature or "bugaboo"?)
Probably you want manga/anime with 妖怪 if you want a list of those with Japanese tastes.
Hope it helps!