S01E12: Side Effects
Ben's summer cold causes strange physical changes in his alien personas.
Previous Episode 
Season 1
And Then There Were 10
S1E1 / 27 Dec 2005
Washington B.C.
S1E2 / 13 Jan 2006
The Krakken
S1E3 / 14 Jan 2006
Permanent Retirement
S1E4 / 21 Jan 2006
Hunted
S1E5 / 28 Jan 2006
Tourist Trap
S1E6 / 04 Feb 2006
Kevin 11
S1E7 / 11 Feb 2006
The Alliance
S1E8 / 18 Feb 2006
Last Laugh
S1E9 / 25 Feb 2006
Lucky Girl
S1E10 / 04 Mar 2006
A Small Problem
S1E11 / 11 Mar 2006
Side Effects
S1E12 / 18 Mar 2006
Secrets
S1E13 / 25 Mar 2006
Season 2
Truth
S2E1 / 29 May 2006
The Big Tick
S2E2 / 30 May 2006
Framed
S2E3 / 31 May 2006
Gwen 10
S2E4 / 01 Jun 2006
Grudge Match
S2E5 / 07 Jun 2006
The Galactic Enforcers
S2E6 / 13 Jun 2006
Camp Fear
S2E7 / 21 Jun 2006
Ultimate Weapon
S2E8 / 06 Jul 2006
Tough Luck
S2E9 / 12 Jul 2006
They Lurk Below
S2E10 / 18 Jul 2006
Ghostfreaked Out
S2E11 / 25 Jul 2006
Dr. Animo and the Mutant Ray
S2E12 / 25 Aug 2006
Back With a Vengeance
S2E13 / 09 Oct 2006
Season 3
Ben 10,000
S3E1 / 25 Nov 2006
Midnight Madness
S3E2 / 02 Dec 2006
A Change of Face
S3E3 / 09 Dec 2006
Merry Christmas
S3E4 / 11 Dec 2006
Benwolf
S3E5 / 17 Feb 2007
Game Over
S3E6 / 24 Feb 2007
Super Alien Hero Buddy Adventures
S3E7 / 03 Mar 2007
Under Wraps
S3E8 / 10 Mar 2007
The Unnaturals
S3E9 / 17 Mar 2007
Monster Weather
S3E10 / 24 Mar 2007
The Return
S3E11 / 07 Apr 2007
Be Afraid of the Dark
S3E12 / 14 Apr 2007
The Visitor
S3E13 / 21 Apr 2007
Season 4
Perfect Day
S4E1 / 07 Jul 2007
Divided We Stand
S4E2 / 14 Jul 2007
Don't Drink the Water
S4E3 / 21 Jul 2007
Big Fat Alien Wedding
S4E4 / 28 Jul 2007
Secret of the Omnitrix (1)
S4E5 / 04 Aug 2007
Secret of the Omnitrix (2)
S4E6 / 04 Aug 2007
Secret of the Omnitrix (3)
S4E7 / 04 Aug 2007
Ben 4 Good Buddy
S4E8 / 22 Sep 2007
Ready to Rumble
S4E9 / 29 Sep 2007
Ken 10
S4E10 / 06 Oct 2007
Ben 10 vs. Negative 10 (1)
S4E11 / 09 Mar 2008
Ben 10 vs. Negative 10 (2)
S4E12 / 09 Mar 2008
Goodbye and Good Riddance
S4E13 / 15 Apr 2008
Tara Strong
Ben Tennyson (voice)
Meagan Moore
Gwen Tennyson (voice)
Paul Eiding
Grandpa Max (voice)
Dee Bradley Baker
Stinkfly / Wildmutt (voice)
Steve Blum
Ghostfreak / Heatblast / Vilgax (voice)
Richard McGonagle
Four Arms (voice)
Richard Steven Horvitz
Grey Matter (voice)
