Big Thunder Mountain Railroad
Isobar appears in the flooded town of Tumbleweed, at the back of his wagon bailing out water. Show guides for the attraction described him further:
" Although the little settlement suffered from bouts of arid weather the arrival of Professor Cumulus Isobar, "Rain Maker Extraordinaire and Purveyor of Magical Elixirs" always guaranteed that his customers would no go dry for long. Sometimes it even chanced to rain while he was in town, enhancing his reputation, and usually resulting in a flash flood, if the ground refused to absorb the rainfall because it had baked too long in the sun."
Cumulus Isobar appears in the first issue demonstrating his supposed rainmaking talents with a cannon. The clouds he creates are enough to fool the onlookers into purchasing his various wares, though Abigail Bullion is smart enough to not take him seriously.
His appearance in the comic is much more kept up in contrast with his animatronic figure and bears a closer resemblance to Doc Terminus.
- Tony Baxter cited the film The Seven Faces of Dr. Lao as inspiration for the Rain Wagon gag Professor Isobar was part of.