Cumulus Isobar

Professor Cumulus Isobar is a character from Magic Kingdom's Big Thunder Mountain Railroad. He is a traveling con-man claiming to be able to summon rain.

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."

Kingdoms: Big Thunder Mountain Railroad
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.

Trivia

 * Tony Baxter cited the film The Five Faces of Dr. Lao as inspiration for the Rain Wagon gag Professor Isobar was part of.