Speaking backwards has been associated at various times with witchcraft and other nefarious purposes: spells often incorporate words uttered backwards.
In an area of Argentina and Uruguay, locals use a type of slang called Lunfardo, which uses backwards words from the various languages spoken by immigrants to the country. These are used in tango lyrics and in everyday speech and can be utilised in creative writing to evoke the atmosphere of the street. Similar slangs are found in other countries, including France, where speaking backwards is known as “Verlan”. In San Cristóbal de la Laguna in the Canaries, enthusiasts campaign to have their local version of speaking backwards recognised by UNESCO as an example of “intangible cultural heritage of humanity.”
Yrev gnitseretni!