That's a mean dog.

那是一只恶狗。

youdao

Her grandfather hated Kelso, thought him a mean dog.

她祖父讨厌凯尔索，认为他是个无赖。

youdao

That's a mean-looking dog.

那狗看上去很凶啊。

《牛津词典》

But I thinkit was her grandma's dog. He was a mean dog.

VOA: standard.other

To look at the dog, you would think he was not worth anything but to sit around and look mean and look for a chance to steal something.

VOA: special.2009.08.29

"That doesn't mean the dog is happy, that means the dog is excited!"

CNN: 'Dog Whisperer' Cesar Millan on adopting the right dog

The state high court ruled that just because a drug-sniffing dog received training and a certificate of graduation does not mean that the dog should be deemed capable of detecting by smell whether an automobile, container, suitcase or other receptacle is hiding illegal drugs.

FORBES: Man's Best Friend Is No Friend to the Fourth Amendment

That would mean that the dog would be whining and turning in circles.

NEWYORKER: Indianapolis (Highway 74)