1. 忘恩负义的家伙：492.到时候就知道了. I'll know when the time comes. | 493. 好戏还在后头呢! You ain't seen nothin' yet! | 494. 忘恩负义的家伙! Ingrate!

2. 忘恩的人：ingestive behavior 摄食行为 | ingrate 忘恩的人 | ingratiation 奉承

3. 忘恩负义者：ingrained 彻底的 | ingrate 忘恩负义者 | ingratiate 使迎合

noun

1. a person who shows no gratitude

Synonym: thankless wretchungrateful person