Aired on: March 18, 2006

A man with the ability to control arthropods decides to attack a councilwoman to stop the demolition of his building. Ben is there to stop him but, after catching a cold, all of his alien forms are also sick.

Tropes:

• 2D Visuals, 3D Effects: The black widow spiders climbing up the councilwoman's body are clearly CGI.
• Ability Reversal: When Ben transforms into the usually-fire-themed alien, Heatblast, he discovers his cold caused Heatblast’s fire powers to be replaced with cold-themed abilities.
• Added Alliterative Appeal: When Ben transforms into Four Arms, who now has cysts on his armpits, Gwen comments on how disgusting they are with this trope:
  Max: It's your hives. The cold must have turned them into pus-filled pockets of–
  Gwen: Pure putridness!
• Artistic License – Biology: Once again, we have the age old myth that cold temperatures cause common colds, which is what happened to Ben. In reality, the worst that could have happened would be hypothermia; colds are caused by viruses. It gets taken to silly extremes with Heatblast, who has the ability to shoot ice, caused by a cold. Although, this has the unfortunate side effect of possibly one of the truck drivers delivering the ice cream he eats as being sick.
• Bee-Bee Gun: Clancy uses wasps as his main attack force as shown when he used them to kidnap the councilwoman or when he made them pursue Gwen and Max.
• Cassandra Truth: The robber that Upgrade stops at the beginning of the episode tells the police officers arresting him that a pilotless motorbike made him crash. Of course, he's describing Upgrade's abilities but no one believes him.
• Cool Bike: At the beginning of the episode, Upgrade turns a regular motorcycle into a bike worthy of TRON.
• Cursed with Awesome: Unlike Wildmutt and Four Arms who end up being handicapped by Ben's cold, Heatblast experiences some useful side effects when his powers are inverted so that he generates ice.
• Death Glare: Max gives one to Clancy when he loses his bug armor.
• Delicious Distraction: Ben uses the medicine Max gave him to distract Clancy's swarm away from the RV.
• Even Evil Has Loved Ones: Clancy is shown to care a lot about the insects that he rears and controls, as well as his childhood home, which was built by his granddad. It's best solidified when after the Tennysons have accidentally wrecked his home and killed most of the insects, Clancy picks up fistfuls of lifeless bugs, staring in shock and grief.
• Foreshadowing: Gwen says that insects are extremely resilient and their only options would be waiting for another ice age, a tank full of pesticide or burning them. Given that they can't use the first two, Heatblast will have to do, but because he's sick he gets ice powers.
• Foul Medicine: Grandpa Max buys Ben medicine to cure his cold, that both tastes and smells terribly.
• Friend to Bugs: Clancy clearly cares about arthropods and is extremely angry when Four Arms kills most of his friends by destroying the building they live in.
• Going Critical: Clancy's plan of destroying the city involves tampering with a nuclear reactor and somehow turning it into a nuclear bomb.
• Here We Go Again!: Gwen ends up catching Ben's cold at the end of the episode, much to her dismay but to the delight of Ben, who recovered from it.
• An Ice Person: Heatblast's powers reverse completely and become ice-based when he has a cold. It allows him to save the day.
• If It Tastes Bad, It Must Be Good for You: The medicine Max gives to Ben naturally has an awful smell, though Max assures Ben that the taste is not as bad.
  Grandpa Max: Don't worry, it smells worse than it tastes. Or was it the other way around?
• Ironic Echo: After he gets sick, Gwen taunts Ben about how he didn't think through before locking himself inside an ice cream truck. Ben then wipes his runny-nose with something he finds lying around: Gwen's new blouse, and hits her back with a similar remark.
  Max: (checks Ben's temperature) 101. Sorry Ben, it's official. You have a summer cold.
  Gwen: Maybe from now on you'll think twice before having snack time inside an ice cream truck.
  (Ben grabs a blouse and wipes his nose on it)
  Gwen: Hey! That's my new blouse!
  Ben: (sneezes, then continues to wipe his nose with it) Maybe from now on you'll think twice about leaving your new clothes just lying around.
• Kill It with Fire: Given their toughness, Gwen says that the only reliable option for getting rid of insects is burning them. It's never actually followed upon because Heatblast obtains ice powers when sick.
• Logical Weakness: Because Wildmutt relies entirely on his sense of smell to percieve his environment, the congestion from Ben's cold leaves him completely blind.
• Malfunction Malady: Ben's alien forms react differently to the common cold. Wildmutt is essentially blind because the mucus clogging his nostrils prevents him from smelling anything, Four Arms turns slightly paler and gets smelly cysts under his armpits, and Heatblast gains ice-based powers.
• Mirthless Laughter: After Clancy's swarm of bugs leaves him due to being attracted to the smell of Max's medicine, Clancy can only chuckle nervously before Max punches him out of the Rustbucket.
• Never My Fault: Even though he is the one who caused Four Arms to become itchy when sending the ants to crawl on him and cause him to accidentally destroy the building as he tries to scratch himself, Clancy blames the Tennysons for the collapse of the building.
• Not Quite Flight: Clancy uses his wasp swarm to float and escape the collapse of his building. He also uses it when kidnapping the councilwoman.
• Oh, Crap!: Once Ben lures Clancy's bugs away from the Rustbucket, all Clancy can do is laugh nervously when Max gives him a Death Glare from behind.
• Pest Controller: Clancy has the power to command arthropods and form an empathetic link with them.
• Red Alert: After Clancy destroys the controls of the nuclear reactor, an alarm goes off with the corresponding red lights. Ben innocently asks if that's a good thing, but Gwen simply answers that a red alert in a nuclear plant obviously means something's wrong.
• Revolting Rescue: When the councilwoman warns the Tennysons not to make any sudden movements that will cause the black widow spiders to act up, a sick Fourarms accidentally sneezes mucus onto the councilwoman, which understandably disgusts her but at least gets the black widows off of her.
• Sick Episode: The main plot of the episode is Ben having to deal with a cold (that also affects his alien forms) while having to stop Clancy and his swarm.
• Sneeze of Doom: Four Arms accidentally sneezes a huge amount of mucus over the councilwoman he is trying to save but that turns out to be a good thing as his snot kills the spiders crawling on her body.
• Spider Swarm: Hundreds of spiders are seen living on Clancy's building and they apparently get along with each other just fine, though that may be because of Clancy's control.
• Squirrels in My Pants: Or ants, to be precise, as Four Arms suffers from it thanks to Clancy. Unfortunately for him, this leads to the Tetramand hopping mad and scratching himself, leading to Clancy's home getting destroyed.
• Technicolor Fire: When Heatblast is sick, the fire on his head changes from yellow to blue. Ordinarily that would mean he's burning hotter, but in truth quite the opposite.
• Termite Trouble: A group of termites destroy in a matter of seconds the wooden floor that Gwen is standing in.
• The Worm That Walks: In a variation, Clancy makes an armor with cockroaches.
• Your Other Left: The trope is played straight when Gwen is trying to ride on Ben (as Wildmutt)'s back after he is rendered "blind" from a cold.