Luffy reared backwards, a lion in a cub's body. He growled and pounced forward, trying to tackle Akainu. He was unable to, merely pushed to the side as the larger lion continued to attack Ace. Eventually, the two lions began running side by side, leaving Luffy in the dust.
By the time Luffy was able to catch up, Ace had been stampeded over by a pack of wildebeest and Akainu was long gone. He pranced down the cliffside and howled at the defeat of the pack's leader. And no, this was totally not a fucked-up rendition of The Lion King.