MariaDB [test]> create user foo@localhost;

Query OK, 0 rows affected (0.000 sec)

MariaDB [test]> grant proxy on 'x-x' to foo@localhost;

Query OK, 0 rows affected (0.000 sec)

MariaDB [test]> show grants for foo@localhost;

+-----------------------------------------------+

| Grants for foo@localhost                      |

+-----------------------------------------------+

| GRANT USAGE ON *.* TO `foo`@`localhost`       |

| GRANT PROXY ON 'x-x'@'%' TO 'foo'@'localhost' |

+-----------------------------------------------+

2 rows in set (0.000 sec)

MariaDB [test]> set sql_mode='ORACLE';

Query OK, 0 rows affected (0.000 sec)

MariaDB [test]> show grants for foo@localhost;

+-----------------------------------------------+

| Grants for foo@localhost                      |

+-----------------------------------------------+

| GRANT USAGE ON *.* TO "foo"@"localhost"       |

| GRANT PROXY ON 'x-x'@'%' TO 'foo'@'localhost' |

+-----------------------------------------------+

2 rows in set (0.000 sec)