are you talking about a part-slime, part-human, a human with slime-y traits, or a sentient slime?
a hybrid would be impossible without mad science, and the specimen would be ugly as sin.(green translucent skin, no bones, would basically look like vaguely human-shaped floppy sludge.)
a human with "the slime blessing" would be double-jointed, have green vaguely translucent skin(enough to see blue veins if you look hard enough), have a tendency to swallow things whole, be more resilient against getting hit, have good night vision, and feel squishy. he wouldn't have slime mannerisms, however, as he was not raised as a slime.
a sentient slime, however, would have all of the above, and more. he'd be sufficiently upright to look like more than a slime pile, because unlike man, he wouldn't have to depend on bones for support. His arms and legs would behave more like tentacles then bony limbs, going every which way. he'd slouch. he'd be very touchy-feely (hugging everyone in sight), and like nice, moist, dark caverns. he'd feel nervous around pointy things and fire. he'd lack a good deal of human intellect, and even some animal instinct, because actual slimes can't think at all. he wouldn't be talking much, if at all.
so in conclusion, a slime-man is either nightmarish, or ridiculous.