Despite the track being MOAB-y dick what really is part of the track is a BFB.
The Monkey on the top part of track is from Bloons 2.
Even though there is water on this track, Monkey Buccaneers cannot be placed on it. It is not known whether this was intentional or not.
Like the Bloons TD5 Mobile trailer's Z.O.M.G., the B.F.B. has a rather creepy smile on the bottom side, below the eyes. This could actually be real on the B.F.B. or Z.O.M.G.. But the player just can't see those teeth in-game due to the top-down view.
The BFB on the track has a mouth just like the BFB in the apopalypse mode symbol in BTD4 iOS.
This is arguably the easiest Extreme Difficulty track because it has only 1 path. All the other Extreme Difficulty tracks have more than 1 path.