A lot of the expert maps currently in bloons tower defense 6 were once impossible to beat in CHIMPS. From Muddy Puddles and #Ouch to Ravine and Bloody Puddles, here's the story of how each map ended up being defeated.
This is certainly not a CHIMPS black border guide video.

Okay I gotta list a ton of credits
Rohan: ‪@RohanSA‬ For being the GOAT
Isab: ‪@BTDIsab‬ For beating muddy puddles and recording literally everything around it making it easy to find
Jajajosh: ‪@Jajajosh‬ For being the other GOAT
Nickthemurph: ‪@nickthemurph-btd6323‬ For being a good player and uploading some early footage of both muddy and quad (The quad run footage was his)
TheDarkLink: ‪@TheCharlieCao‬ For beating #ouch
WezleyNZ deleted everything from quad but he beat it first
Shoutout the Please Enjoy Coffee Bar in Santa Monica for having a cool logo