A couple decide that they need a guard dog.
So the guy goes to a pet shop and says to one of the employees, “I need a guard dog to protect my apartment”
The employee responds, “I have the perfect dog for you”, she then showed him a chihuahua.

The man was not impressed and said, “I need a dog that can guard our house and fend off burglars, a chihuahua can’t do that.”
“But this is no regular chihuahua. It’s an attack chihuahua!” the employee said, “Here, I’ll show you how it works! Attack chihuahua, chair”
The employee pointed at a chair, and the guy and the employee watched as the chihuahua destroyed the chair, leaving only splinters behind.
“Wow,” the guy said “But I still think we need a real guard dog.”

“Are you sure?” she responded “Here I’ll show you again. Attack chihuahua, table!”
She pointed to a table, and, again, the chihuahua absolutely destroyed the table.
The man said “Okay, okay, I’ll take it.”

When he brought it home, his wife was very angry.
“Why did you buy a chihuahua?!” She yelled
“Because” he responded, “this is no ordinary chihuahua, this is an attack chihuahua!”
“Attack chihuahua, my ass!” she responded