This was a short commercial shown in foreign countries on Cartoon Network. It's fairly certain this was never released in the USA.
Batman teams up with Ben Tennyson, in his Grey Matter form, and they take out a couple of thugs. While later, in the Bat-Cave, Batman is keeping an eye on Gotham City with his Batcomputer. Just then, Ben notices the Bat-signal. Immediately Batman runs into action, but he accidentally steps on poor Ben, who is very small while in his Grey Matter form.