Verses with the word unthankful in the Apocrypha (3 verses):

2 Esdras 8:60
But they which be created have defiled the name of him that made them, and were unthankful unto him which prepared life for them.

Wisdom of Solomon 16:29
For the hope of the unthankful shall melt away as the winter's hoar frost, and shall run away as unprofitable water.

Sirach 29:17
And he that is of an unthankful mind will leave him [in danger] that delivered him.