In “the notorious jumping frog of calaveras county” by mark twain, what adjectives best describe the character of jim smiley? idealistic, dreamy realistic, funny comic, exaggerated credible, genuine

The best answer is "comic, exaggerated". 

Jim Smiley is clearly a funny character, betting on rather arbitrary things like how far a frog can jump. He's exaggerated in the sense that he'll bet a large sum on pretty much anything ($40 in Mark Twain's day was roughly a thousand dollars today!) 

He is a funny and and out-there character, especially considering that the narrator was looking for a Reverend Smiley, about as far from Jim Smiley as a person could be.