为了夺回收缩射线枪，格鲁决定领养三位孤儿——玛戈、伊迪丝和阿格蕾丝，利用她们进入维克托的城堡兜售饼干的机会实施偷盗，计划成功后再偷偷处理掉三个小孩。
于是格格巫派出韦克茜混入大森林，绑架了即将迎来生日的蓝妹妹，希望能从她口中拷问出蓝爸爸将她变蓝的秘密。
然而在平凡的日常相处中，格鲁却发现自己越来越离不开这三个小鬼，但这样的感情用事却将严重影响周密的盗月计划…… ……
精彩片段对白：
Dr. Nefario: We've been working on this for a while. It's an anti-gravity serum. I meant to close that. He'll be all right, I'm sure.
Gru: Do the effects wear off?
Dr. Nefario: So far, no. No, they don't. And here, of course, is the new weapon you ordered.
Gru: No, no. I said "dart gun," not... Okay.
Dr. Nefario: Oh, yes. 'Cause I was wondering under what circumstances would we use this? But, anyway. What I really wanted to show you was this.
Gru: Now those are cookie robots!
Agnes: La, la, la, la I love unicorns...
Gru: What are you doing here? I told you to stay in the kitchen!
Margo: We got bored. What is this place?
Edith: Can I drink this?
Dr. Nefario: Do you want to explode? Gru!
Gru: Get back in the kitchen!
Agnes: Will you play with us?
Gru: No.
Agnes: Why?
Gru: Because I'm busy.
Margo: Doing what?
Gru: Okay, okay, you got me. The dentist thing is more of a hobby. In real life, I am a spy. And it is top secret, and you may not tell anybody, because if you do...
Edith: What does this do?
Gru: Hey!
Edith: Oops.
Agnes: My unicorn! You have to fix it.
Gru: Fix it? Look, it has been disintegrated. By definition, it cannot be fixed. That's freaking me out. What is she doing?
Margo: She's gonna hold her breath until she gets a new one.
Gru: It is just a toy. Now stop it! Okay, okay! I'll fix it! Tim! Mark! Phil! This is very important. You have to get the little girl a new unicorn toy. Hey, hey, hey! A toy! Go, and hurry!
Margo: What are those?
Gru: They are my cousins. Jerry! Stuart! Watch them, and keep them away from me, please.
Minions: Wow! Wow!
Edith: It was your cousin's idea.
Jerry: What?
Gru: Okay, bedtime. Not you two! Okey-dokey. Beddie-bye. All tucked in. Sweet dreams.
Margo: Just so you know, you're never gonna be my dad.
Gru: I think I can live with that.
Edith: Are these beds made out of bombs?
Gru: Yes, but they are very old and highly unlikely to blow up. But try not to toss and turn.
Margo: Cool.
Agnes: Will you read us a bedtime story?
Gru: No.
Agnes: But we can't go to sleep without a bedtime story.
Gru: Well, then it's going to be a long night for you, isn't it? So, good night, sleep tight, and don't let the bed bugs bite. Because there are literally thousands of them. And there's probably something in your closet.
Margo: He's just kidding, Agnes.
Agnes: It's beautiful.
