Arnold'ın ailesi kayıptır.Çılgın büyükannesi ve öğüt dolu büyükbabasıyla yaşamaktadır. Çok sayıda evcil hayvanları vardır, ancak Arnold en çok Abner isimli domuzdan hoşlanmaktadır. En yakın arkadaşı Gerald'dır. Helga adlı başına bela olmuş bir kız vardır. Aslında Helga Arnold'a deli gibi aşıktır ama Arnold bunu bilmemektedir ve sonuna kadar da bilmeyecektir. 118 Nolu okulda okuyarak ve inanılmaz değişik maceralar yaşayarak hayatını geçirmektedir.
Out of Control (1984) • Double Dare (1986) • Don't Just Sit There (1988) • Hey Dude (1989)
1990'lılar
Wild & Crazy Kids (1990) • Salute Your Shorts (1991) • Fifteen (1991) • What Would You Do? (1991) • Clarissa Explains It All (1991) • Welcome Freshmen (1991) • Are You Afraid of the Dark? (1991) • Doug (1991) • Rugrats (1991) • The Ren & Stimpy Show (1991) • Nickelodeon Guts (1992) • Roundhouse (1992) • Legends of the Hidden Temple (1993) • The Adventures of Pete & Pete (1993) • Rocko's Modern Life (1993) • My Brother and Me (1994) • Aaahh!!! Real Monsters (1994) • The Secret World of Alex Mack (1994) • All That (1994) • Space Cases (1996) • The Mystery Files of Shelby Woo (1996) • KaBlam! (1996) • Kenan & Kel (1996) • Hey Arnold! (1996) • The Journey of Allen Strange (1997) • Angry Beavers (1997) • Animorphs (1998) • Cousin Skeeter (1998) • Oh Yeah! Cartoons (1998) • The Wild Thornberrys (1998) • CatDog (1998) • 100 Deeds for Eddie McDowd (1999) • The Amanda Show (1999) • Rocket Power (1999)
2000'liler
Noah Knows Best (2000) • Caitlin's Way (2000) • The Brothers García (2000) • Pelswick (2000) • As Told by Ginger (2000) • The Fairly OddParents (2001) • Invader Zim (2001) • Taina (2001) • Action League Now! (2001) • The Nick Cannon Show (2002) • ChalkZone (2002) • Jimmy Neutron (2002) • Romeo! (2003) • My Life as a Teenage Robot (2003) • All Grown Up! (2003) • Danny Phantom (2004) • Drake & Josh (2004) • Ned's Declassified School Survival Guide (2004) • Nicktoons Film Festival [t] (2004) • Unfabulous (2004) • Avatar: Son Havabükücü (2005) • Catscratch (2005) • Zoey 101 (2005) • The X's (2005) • Just for Kicks (2006) • H2O: Just Add Water (2006) • Kappa Mikey[t] (2006) • Mr. Meaty (2006) • Just Jordan (2007) • El Tigre: The Adventures of Manny Rivera (2007) • Shorts in a Bunch [t] (2007) • Wayside (2007) • Edgar & Ellen [t] (2007) • The Naked Brothers Band (2007) • Tak and the Power of Juju (2007) • Back at the Barnyard (2007) • iCarly (2007) • Dance on Sunset (2008) • Speed Racer: The Next Generation [t] (2008) • Making Fiends [t] (2008) • Angelica and Susie's Pre-School Daze (2008) • My Family's Got Guts (2008) • Random! Cartoons [t] (2008) • Three Delivery [t] (2008) • The Mighty B! (2008) • True Jackson, VP (2008) • BrainSurge (2009) • The Troop (2009) • Fanboy and Chum Chum (2009) • Big Time Rush (2009)
2010'lular
Victorious (2010) • Planet Sheen (2010) • T.U.F.F. Puppy (2010) • Anubis Evi (2011) • Supah Ninjas (2011) • Power Rangers Samurai (2011) • Voltron Force[t] (2011) • Bucket & Skinner's Epic Adventures (2011) • Fred: The Show (2012) • How to Rock (2012) • Robot and Monster (2012) • You Gotta See This (2012) • Marvin Marvin (2012) • The Legend of Korra (2012) • Wendell & Vinnie (2013) • Figure It Out (1997; 2012) • Monsters vs. Aliens (2013) • Sam & Cat (2013) • Gürültü Ailesi (2016) • Casagrande Ailesi (2019)