Cow and chicken.

Cow and Chicken is an American animated series, created by David Feiss. The series shows the surreal adventures of a cow, named Cow, and her chicken brother, named Chicken. They are often antagonized by "The Red Guy", who poses as various characters to scam or hurt them. 

Cow, is Chicken's 7 year old sister, with a weight stated as 600 pounds. Cow looks up to Chicken, who she refers to as "Big Brother". She is often viewed by Chicken as infantile and stupid, and is quickly prone to emotional outbursts. She is the only character to appear in every episode of the show. Cow has employed Blackmail to get Chicken to do what she wants and often attempts to get the other characters to do the right thing. Cow's alter ego is "Supercow", a superhero with the ability to fly. 

Chicken, is Cow's 11 year old brother. He can be mean to his younger sister, and even to the rest of the family. He has a powerful ego, but in spite of this, has a powerful conscience, usually only displayed when Cow is in danger. His speech is riddled with malapropisms and sarcasm. Despite being a male, he demonstrated the ability to lay eggs. Chicken is very fond of ice skating. Like other chickens, he cannot fly, and is afraid of flying. Chicken is the only character in the show who knows that his sister and Supercow are the same person. 

source: http://en.wikipedia.org/wiki/Cow_and_Chicken

http://www.youtube.com/watch?v=6zXIScJ1LT8

Cow and Chicken are two characters that represent very well each one of our concepts. Cow is the personification of Robust, both physically and in personality. Chicken, instead, is the personification for Fragile. 

Johnny Bravo

Johnny Bravo is an American animated television series created by Van Partible for the Cartoon Network. The series stars a muscular beefcake young man named Johnny Bravo, who dons a pompadour hairstyle and Elvis Presley-like tone of voice personality. Plots typically revolve around him trying to get a woman that he has targeted throughout the episode to fall in love with him. He is often beat up or stunned by his target or companions, or gets ditched by them in the end.

Johnny Bravo is a funny character because he pretends to be all strong and robust but in reality he is really very sweet inside and care a lot about his friends and his mother.

Popeye & Olivia: opposites attract

Popeye the Sailor is a fictional hero notable for appearing in comic strips and animated films as well as numerous television shows. He was created by Elzie Crisler Segar, and first appeared in the daily King Features comic strip Thimble Theatre on January 17, 1929. Olive Oyl is actually older than Popeye, she appeared in the comic strip Thimble Theatre since  1919. The strip was later renamed Popeye after the sailor character that became the most popular member of the cast; however Olive Oyl was a main character for 10 years before Popeye's 1929 appearance.

In the films and later television cartoons, Olive Oyl is Popeye's girlfriend, although she could be extremely fickle, depending on who could woo her the best or had the flashier possessions, and was prone to get angry over the tiniest things. She constantly gets kidnapped by Bluto(aka Brutus), who is Popeye's archrival for her affections, but Popeye always rescues her, winning her affection in the end.

Source: http://en.wikipedia.org/wiki/Popeye

This particular couple exceptionally represents the fragility and the robustness, he is strong and brave and she is weak and always in distress. Physically they are also very different, he it short but muscular and she it tall and boney, but it their love for each other that keep this awkward couple together. 

House of Cards

In this image the "robustness" is portrayed by a house of cards, which is made of fragile pieces of paper (cards). The cartoon shows how together they can create a strong solid stucture, but that the same one can be easily destroyed due to it's weak fundations.

Despicable Me

 

Trailer retrived from: http://www.youtube.com/watch?v=4LuGnKmmDDw

This trailer shows how a plastic balloon, which is a fairly fragile object, can be robust at the same time when inflated with air. When the little boy hugs the balloon animal this one remains intact, but when the man touches it with a needle, this one pops.