Here's what rhymes with swallowtail.
pale tail tale jail bail bale dale pail male fail mail sale sail trail nail rail veil gale hail shale whale stale vale wail hale braille kale faille wale detail scale avail entail frail email assail curtail quail snail flail quale bewail derail grail impale hightail prevail travail inhale pigtail ponytail topsail unveil foresail taffrail bobtail wassail pellmell lugsail carrell exhale gunwale mainsail martingale monorail hangnail tattletale fingernail countervail nonpareil