It is related that the 19th century poet Robert Browning boasted he could make a poem to rhyme with any word. A man at his London club challenged him: What about Timbuktu?
Once a Cassowary
in Timbuktu
Ate a missionary
and his hymn book too.
Missionary needs to be said as “mission airy”. A Cassowary, since you ask, is an ostrich-like bird native to New Guinea; hence unlikely to be found in Timbuktu. The word rhyme has an interesting history. Until the 17th century it was written rime, derived from Old French. My English teacher, Mr Dumbreck, told us that it was changed to rhyme due to false etymology, associating it with rhythm (of Greek origin). However the OED says that ultimately the English word rime and the Greek word rhythm do have the same source, so perhaps Mr Dumbreck was a little too severe.