"Mad Amos" is a short story collection (or anthology) about a very big man named Amos Malone and his "horse" Worthless, written by Alan Dean Foster. Foster is a prolific science fiction writer, but more known for his numerous novelizations.
All the stories, except one, have the main character as Amos Malone or as many say, Mad Amos. Obviously, many think of him mad not only because he is a mountain man (i.e. he lives alone in the mountains), but also because his weird manners and knowledge and a very curious "horse" named Worthless, which can carry a man of Malone's weight, has something covering the forehead and an unusual intelligence.
This book has ten stories, with quality ranging from ok-ish to great, all with an interesting weirdness. Even if Malone lives in the period of cowboys and the American Old West (which I don't consider to be very prone to fantasy), the stories involve dragons, spirits, jackalopes and much more. Some of the ideas don't seem to quite fit in the whole concept, but in the overall the result is funny and entertaining.
The writing isn't anything imaginative or brilliant, but the occasional wordplay makes it fun and sometimes worthwhile.
Recommend if the idea of a reinvented Old West, filled supernatural beings appeals to you.
Till next time,
M.I.T.H. (ManInsideTheHelm)