An American Tail
In the original story a young Fievel is forced from his home by antisemitic violence in his native Russia and boards a ship setting sail for America along with his family - they believe America will be the land of opportunity and sing "There Are No Cats In America" to empathise this, as cats were traditional oppressors of mice in Fievel's setting.
However on the way to their new land a storm causes havoc and washes Fievel overboard, separating him from his family as he is washed out to sea - yet instead of drowning he survives and manages to wash ashore on the outskirts of New York city: the rest of the movie concerns his brave quest to reunite with his family and the opposition he faces from a variety of villainious individuals, the most prominent of which is Warren T Rat: a con man and cat in disguise who seeks to cause trouble for the immigrant mice as part of an extortion scheme.In the first film Fievel meets up with a kindly French pidgeon named Henri who helps lift the mouse's spirit after he is washed ashore in America via the musical number "Never Say Never" - he then has his fellow pidgeons take Fievel to immigration, as Henri knows everyone goes through immigration - he says to Fievel that he would accompany him but then he would never finish "his" statue (refering to the as of then near-complete Statue Of Liberty).
However Fievel was led astray by Warren T Rat, who tricked him with false hope - stating he knew where to find his family - in reality Warren T cruelly used Fievel's trust to sell him into slavery in the form of a sweatshop, however despite cruel treatment by the fellow orphans in the establishment he secretly never gives up hope of finding his family again, as expressed in the musical number "Somewhere Out There".
Eventually Fievel manages to escape the sweatshop with the help of Tony, a young mouse who Fievel managed to befriend and who would continue to be his ally in most of the sequels (minus Fievel Goes West).
After once again becoming lost Fievel encounters Tiger for the first time, although frightened of the feline at first Fievel soon comes to realize that Tiger is harmless and the soft-hearted cat frees him from the cage that Warren T Rat had imprisoned him in after Fievel found out that the so-called "rat" was in reality a cat, although this cost Tiger his position as a minion of Warren T Rat he seemed happy enough: stating that he never liked Warren T to begin with.
By the time Fievel does find his family again the mice have had enough of Warren T Rat and his gang of thugs so come up with an ingenious plan to scare the cats away using a mechanic device based on an old story - this device succeeds in sending Warren T Rat and his gang into the sea, where they are seen hitching a ride to Hong Kong: Warren T's last words are "I wonder how you say "trust me" in Chinese..".
During the climatic battle however Fievel almost loses his family again and becomes deeply upset, yet his father had quick-thinking and played his violin - the music led Fievel back to his family, the story ends with Henri returning in order to show everyone "his" completed statue and Fievel begins his life in America..
An American Tail: Fievel Goes West
In Fievel Goes West the young mouse becomes an Old West hero after his family are tricked into moving out West by the villain known as Cat R Waul - Fievel is once again separated from his family but joins forces with Tiger and Sheriff Burp to take down Cat R Waul and his gang before they can turn the mice into mouse-burgers.
An American Tail: The Treasure Of Manhattan Island
In The Treasure Of Manhattan Island Fievel befriends a group of Native American mice and aids them against the cruel antics of a gang of rich sweatshop owners, who are also making Fievel's father's life miserable along with many of their workers in their pursuit of money and power.
An American Tail: The Mystery Of The Night Monster
In the final sequel Fievel becomes ensnared in a mystery involving a supposed monster that is kidnapping mice, however this monster is soon revealed to be a mechanical device created by the villainious Madame Mousey - a miniature French poodle with a hatred of all things rodent.
Fievel was brave but perhaps a little foolish, like most young boys - he believed in sticking up for himself and others but didn't always think things through and this could led to trouble as he would often try to take on enemies much larger and stronger than himself but it also made him stand out from the usual stereotype of a mouse, which is a timid creature.
Fievel was also optomistic and rarely gave up hope even under the most extreme of circumstances - yet he was still quite young and as such required a family to take care of him and provide him with warmth and security, Fievel's desire to be with his family was strong enough that he braved all manner of danger to be with them and in many ways is a tribute to his strong will and determination.
Powers & Abilities
Fievel didn't have superhuman abilities or talents but was naturally quick and agile and likely had all the usual abilities of a mouse - such as enhanced senses, his most powerful tool was always his mind and he showed great intelligent and wisdom throughout the series despite his young age.