Pumped Up! ~ Big Musculature in Mammalia ;-)

Whoa, I just saw the trailer for Bigger Stronger Faster......and it's gotten me thinking about all the ways we naturally and artificially pump up Mammalia. Outlier humans like this bodybuilder with massively steroidal arms (in 'cuffs for distributing the drugs, something the libertarian in me rejects -- the illegality, that is)......and outlier bovines such as the Belgian Blue supercow resulting from a natural myostatin gene mutation...