not really that hard to make. if its just 1 word check it with $event->getMessage(), assuming you have $event defined. If not arrays will be handy
ChatCensor by EvolSoft does this: the github repo is here https://github.com/EvolSoft/ChatCensor, but it hasn't yet been updated for the latest API version, or added to Poggit yet... Maybe if you ask the author he'll do it.
i doubt that's what op wanted maybe op wanted a CONFIGURABLE replacement plugin like a into abc b into bcd c into cde and so on...
That's what I understood, and it does indeed do that too, but you need to enable it in the config for each word: https://github.com/EvolSoft/ChatCensor/blob/master/src/ChatCensor/EventListener.php#L107