A search through Fairbairn's Crests shows the motto "Fear not" being used by Dawes, and "Fear nought" being use by Ramsay.
But looking at the crests used by Dawes and Ramsay, there are no lion's heads erased, the crest here. (The Ramsays used mostly unicorn's and horse's heads; Dawes, other charges.)
Sorry! So far, we don't have an identification for you.