Rugrats

Rugrats was a long running animated show on Nickelodeon about four babies, Tommy, Chuckyy, Phill and Lill who, unbeknownst to their parentsm can talk to each other. Additional characters include  an older toddler named Angelica who is the antagonist of the series, Angelica's best friend Suzi and Dill, Tommy's lttle brother who was added in the fourth season. A lot of the humor in the show comes from the babies misunderstanding words that are said by their parents, for instance the babies refer to the Gand Canyon as The Grahm Canyon. Despite their small size, the babies have been shown to expose unscrupulouss adults as well as minor criminals, the adults however don't take this as anything out of the ordinary instead relating these occurrences to blind luck., 
 
 Rugrats had a somewhat intresting broadcast history. New episodes were routinely broadcast form 1991 until 94 at which point production was essentially shut down yet reruns continue to air. In 96 Nickelodeon broadcast a new episode-a passover special, and in 1997 new epiisodes went into production, It is thus the longest running nicktoon, if one includes the three year hiatus. 

In 2001 Rugrats cellebrated it's tenth anniversery with an episode titled "all growed up" that took place nine years in the future, the series was so successful Nickelodeon commisioned a spin off series based on the episode. The spinoff series All Grown Up premiered on April 12th 2003 and lasted for five seasons before being canceled in 2008. Meanwhile the regular Rugrats show went off the air in 2004 with two direct to video episodes released in 2005 and 2006.