Apparently a lot of forgotten Hanna-Barbera shows are actually hugely iconic in other countries. Parts of Europe love Wacky Races, and Top Cat is unbelievably popular in Mexico.
Mexico and Latin America are the reason Top Cat got two movies. The first one, at least, did well in those regions but the English dubs tanked.
Another series popular in those regions is Here Comes the Grump, which is also getting a movie. If it gets an English dub, it'll be interesting to see how it's recieved, because while obscure in English-speaking countries, it does have an interesting trait - it is literally the Adventure Time of 1969.