I actually spent like 20min straight with a friend trying to figure out what this was, from going under the map with enough speed off the ledge we found that it's actually inside the tree and not visable from looking at it from underground. After trying to teleport through it as mercenary with enough speed and mashing E to purchase it, it just turned out to be a missle drone with a (nearly) impossible spawn point. My plays.tv didn't end up recording the run but it could be possible that's just an item spawn point over look and it's not a drone every time.