Because pepper makes them sneeze
or
Does Boston stop at this train?
or
Three skunks fighting over a pickle
First dog: My master calls me Furball. How about you?
Second Dog: My master calls me Sitboy
or
Because an undocumented worker has been living on his head for the past 2 decades!
or
2 years old.
Cow: "Mooooove over"
Sheep: "Naaaaaaa."
or