https://en.wikipedia.org/wiki/Language_game

Language games are simple transformations of words, syllables or letters. Usually parts of a word are replaced or exchanged according to a fixed scheme.

GC Wizard knows the following game and fun languages:

• Chicken language
• Spoon language
• Pig Latin
• Robber language

In addition there are languages, which fall rather into the range of codings and/or ciphers:

• Duck speak
• Kenny’s language