"What'cha talkin' 'bout, Cricket?" - Chase (voiced by Carson Minniear).

Here is the Diff'rent Strokes closing credits video. No Copyright Infringement Intended!
From the episode "Bullmia", the 13th episode of season 8. capped from an old 2008 BET rerun.

NOTE: This is Dana Plato's final appearance in the series as Kimberly Drummond.

FUN-FACT: The episode is titled "Bullmia". it originally aired on ABC on Friday, January 17, 1986.