I agree with
Dual-san.
The Drum Kingdom arc was there only to introduce Chopper. Even though Wapol is a "villain", he's just a funny and stupid guy used to introduce more humor to the series- even though he's cruel, and evil (in a stupid way, of course).
Episode 89 was really cool. Luffy using the Gomu Gomu no Bazooka in Wapol was cooler in the anime than in the manga. Maybe this arc will end next episode, and then Mr.2 will appear in episode 91? Really, I NEED to see him in anime! OKAMA PRIDE!