Mike Posner Resumes Walk Across America After Snake Bite

Mike Posner won't let a near-fatal rattlesnake bite keep him from completing his walk across the U.S. of A. ... because the dude's back on the trail and more determined than ever!!!

The "Cooler Than Me" singer hopped on "TMZ Live" Thursday as he continued his journey from New Jersey to California, detailing his scary encounter with a rattler that nearly took his life.

Mike describes his injury in excruciating detail ... explaining how the baby rattlesnake's venom coursing through his veins had him feeling like he was in the closing credits of a "Looney Tunes" cartoon. Really paints a picture.

Remember ... a rattler tore into Mike's foot last month, after walking 16 miles through the middle of nowhere in Colorado and looking to log 8 more. The bite was as bad as it looked. Mike was airlifted to a hospital and placed in ICU for days, putting his trip across America, like his foot, on ice.

But, Mike's no quitter ... he's picking right up where he left off -- the site of the snake bite -- and says he even saw a few more rattlers on his way toward Arizona.

Mike appeared last April on "TMZ Live," telling us how the deaths of his father and Avicii inspired him to cross the country on foot.

Mike's been releasing new music along the way -- every time he crosses a state line -- and when he gets to Arizona in a few days, he's got a new song -- "Slow It Down" -- for his fans.

Mike feels anything but snake bitten.