4) Bat-Cow
So you don’t find the idea of a Bat-Hound ridiculous enough? Then try this one on for size: Batman has also had a Bat-Cow. No, really. A Bat… Cow.
Damian Wayne’s Robin rescued the animal from the slaughterhouse, whereupon it was noticed that it miraculously had a naturally-grown bat-shaped mask over its eyes. To complete the look it was given one of Batman’s capes and – voila – Bat-Cow was born. And a valued member of the Bat-family it is, too. A well-timed moo from Bat-Cow is enough to brighten Bruce’s spirits.
See below:
The bizarre thing here is that Bat-Cow isn’t from the Silver Age but is actually a modern creation. He first featured in children’s comic Tiny Titan’s Pet Club before Grant Morrison thought the idea was a hoot so included him in proper Batman continuity.