Ah, Aldous Snow. Remember the so-Euro Lothario with the hit single "Inside You" from Forgetting Sarah Marshall, played to the max by Russell Brand? Of course you do. But how did Brand land that hilarious role? In part, it was with an amazing audition (I'm willing to wager that, like, 5 percent of it was his hair). In fact, in Russell Brand's audition tape for Forgetting Sarah Marshall , you'll see not only how he won over the producers and casting directors with his natural hilarity, but also how a large part of Brand's natural mannerisms went into the character of Aldous. Basically, Aldous Snow would not be Aldous Snow without Russell Brand.
You'll see that Brand — who very impressively improvised what you're about to see — does something that few actors can do when they're playing a character who says, and sings, in Aldous Snow's case, a lot of ridiculous things. Yes, Brand is entirely committed, but rather than being enraptured by a pseudo-serious energy, he's just... himself. Therefore, the silly things that come out of his mouth (see his impeccable horse neighing skills) seem totally natural.
Check it out below. But seriously, watch for the neighing.
Also, in case you need a memory-jump, here's "Inside You," the most BEAUTIFUL LYRICAL BALLAD OF ALL TIME. (JK — but it's pretty funny.)