bite one’s head off千万别理解成“把某人的头咬掉了”，这个短语的意思是“大发雷霆；大发光火”。也可以表示表示的是：对某人乱发脾气，把某人骂得狗血淋头。

【例句】
His mother nearly bit his head off when he got his new shoes dirty.
当他把新鞋弄脏时，他的母亲对他大发雷霆。

I'm very sorry I lost my temper, I didn't mean to bite your head off.
很抱歉我发脾气了，我不是故意对你恶语相向的。