MySQL column that auto generates data, longer than UUID
You can create the pair of triggers ON INSERT and ON UPDATE that perform any desired transformations 'on the fly'

CREATE TRIGGER `myuuid_autoinserter` 
BEFORE INSERT ON `table` -- or BEFORE UPDATE
FOR EACH ROW 
BEGIN
  SET loooonguuid = CONCAT(OLD.uuid, OLD.uuid, OLD.uuid, OLD.uuid)
  SET NEW.uuid = loooonguuid;
END


When you run some INSERT or UPDATE query on the table trigger will replace submitted value of the uuid by string stored in the loooonguuid variable.

Sure you can do as complex and randomized transformation as you want.