Dr. Fooler is a greed scientist which appeared in several versions of Tetsuwan Atom and other series.
In the 1950 manga and 1963 anime he invented a machine which made robots gone nuts.
In a story called Count Bat he wanted to buy Atom at any cost and even made a mini-Atom to help him when he lost his legs:
It served as a basis for the 2003 series episode Micro Machines.
He also appeared as the greedy owner of a saffari in the 1980 series and wanted Dr. Ochanomizu to finish a violent robot elephant.
There is a version of that story in the mangá, but Skunk was involved instead of Dr. Fooler.
In the 2003 series, Dr. Fooler was renamed as Dr. Minimini and attempted to capture Atom in order to study and mass produce copies from his design.
But, his henchman ended up infecting Uran instead, but Dr. Minimini went with a backup plan to use a Mini-Atom which would be destroyed by his nano-robot, so Atom's brain would be destroyed and his body would be stolen.
However, his plan failed and Atom rescued his own body.
He would later returns tricking a father into making a machine which would make people see illusions, but his plan failed once again and he was arrasted.
In other series, he was also in Black Jack manga during Pinoko's debut:
I haven't saw the anime episode which shows Pinoko's origins.
In Don Dracula, he was Dr. Van Helsing.
I bet he was in Marvelous Melmo anime as well, but as far I know, he was not in the manga.