Wicket is definately one of the primary characters of the series, often the main character but then again, not always. He generally helps out in all situations while trying to become a big warrior as fast as possible.

Princess Kneesaa:
Daughter of Chief Chirpa, her mother died when she was young. Kneesaa, her sister Asha, and her mother were on a trip when they were attacked. Kneesaa was told to get help but by the time she did her mother was dead and Asha was gone only to come back years later (see episode "Asha").

Teebo is young friend of Wicket who studies under Logray and has a special way to communicate with nature. He uses magic throughout the series to help and hinder the group. The SW Encyclopedia also notes that he is "one of the leaders of the tribe that befriended Princess Leia Organa" although in the series he is way to young for that....

A young Ewok and the little sister of Teebo who had a huge crush on Wicket. (Shown on right of Wicket.)

The best friend of Priness Kneesaa, Latara is a young Ewok who loves to play her flute as well as play pranks but she is a bit selfish at times.

Chief Chirpa:
Head of the Ewok Council of Elders. He helps the tribe throughout the series and basically serves as the head. We never see a Council discussed actually.

The Ewok medicine man and a once great warrior, Logray proves his strength, intelligence, and magic powers over the episodes. He taught Teebo and Wicket as successors, during this series Teebo is the student. He also protected the "Sun Star" an important part of several episodes. According to the SW Encyclopedia, Logray could be a bully and was replaced by Paploo as medicine man after the Battle of Endor.

The powerful and magical Tulgah witch who rivals Logray. She lives in the side of the volcano, Mount Thunderstone where Yuzzums patrol the area atop rakazzak beasts.

Thin, bug-infested creatures are unbelievably distant relatives of the Ewoks. They live in the swamps on Endor and pester the Ewoks frequently headed off by King Gorneesh.

King Gorneesh:
The dimwitted leader of the Duloks.

An Ewok scout (stole speeder in ROTJ as distraction) and was named shaman after Logray.

Erpham Warrick:
A great Ewok warrior who built the Ewok battle wagon ("Wicket's Wagon" - Season One) that defeated the Duloks. He was also Wicket's great-grandfather.

Small elflike creatures that live in a volcanic structure on Endor. Gupin can change forms but others thoughts can evidentally help them concentrate.

Deej Warrick:
The father of Wicket and husband of Shodu. In one episode his children must find several special ingredients to save their dad who is sick.

A traveling "gypsylike" tribe that wanders Endor's forest moon. They make money by trading and their circus-like shows but frequently get lost.

Gracca is an evil flying character who lives on a floating mountain and has a magical Crystal Cloak which makes it so everything he touches turns to crystal.

Leaf Queen:
The Leaf Queen was an odd women of fall. Wind would start blowing to signal her before she appeared. She came and gave Kneesaa a magic plant that gave you what you wished. It almost died but soon came back to life after Kneesaa gave it some special care. The Leaf Queen arrived back to get her plant with seconds to spare.

The Gorphs are a frog-like species who hop around and have amazingly long tongues.

Queen Slugga:
Queen Slugga is the Queen of the Gorphs who is looking for a princess for her son. Previous possibilities failed and she decided to get an Ewok princess to marry her son. She manages to capure Latara who is Princess for the day under Kneesaa's suggestion with the secret motive so that Latara can see how hard it really is to be a Princess.

Asha is the long-lost older sister of Princess Kneesaa. Asha, Kneesaa, and their mother, Ra-Lee were attacked by a hanadak when they were younger. In the episode Kneesaa told her friends that her mother was killed trying to save her and Asha and Asha was found later (though the Encyclopedia says she ran to the village). The only thing found left of Asha was part of her clothing. It was found later that Ra-Lee told her to swim across the nearby river to safety but she couldn't make it and was swept down stream where she was found by a family of korrinas, wolf-like creatures. When found she was consistantly stopping Duloks from trapping animals under the name of the Red Ghost due to her red fur.

Larry (from "Home Where the Shrieks Are") is three-eyed pink character. Teebo and Wicket move out of the village and into his tree where he acts like he is a race called the "Shrieks" and he attempts to scare off the unwanted visitors by making noise and sounds through different audio tubes. When found out he seems friendly and ends up eating everything in sight at the Ewok party that night.

The Raich is an evil monster who appears to be normal tree when Wicket finds it and takes a magical cap off of it. It turns out that the tree is a monster who uses special powers to call unknowing animals to him to devoir. The magical cap Wicket removed turns out to be a very old hat covering the monster's special tubes to call the animals and also turning him into a harmless tree.

The two-headed Gonster is an odd creature that constantly argues with itself but is also the creature that made the original magic hat to make the Raich harmless. After the Raich tears up the previous hat the Gonster helps create a new one arguing with itself about ingrediets the whole time.

The Totem Master:
The Totem Master is an odd looking creature with a magic ring that turns beings into wood for his totem poll. The Totem Master went around giving his special totem poll to different communities and at night uses his ring to make the creatures on the poll come to life to steal from the village. Teebo and Latara are added to the totem poll before they can be saved.

Shodu Warrick on the RightShodu Warrick:
Wicket's mother and the wife of Deej Warrick.

Rakazzak beasts are spider-like, three-meter-tall creatures that are often ridden by Yuzzum warriors who are frequently used by Morag. The Rakazzaks can spin thick, sticky webs to trap their enemies.

Yuzzum Warriors:
The Yuzzums are fur covered beings with long, thin legs, and a wide mouth of sharp teeth. Yuzzums are semi-intelligent but somewhat barbaric spear-wielding creatures. Their favorite meals are small rodents called ruggers. A small few have left to seek fame. Among them is Joh Yowza who joined the Max Rebo band.

Baga is a baby bordok (horse-like animal) and the pet of Wicket. Baga helps throughout the series and listens well but is frequently startled and runs off.

Dr. Raegar:
Dr. Raegar from "Battle For the Sunstar", the last episode to be aired, comes to Endor in an Imperial Star Destroyer to steal the Sunstar. The Ewok kids along with a robot from the Imperials, team up to steal back the Sunstar. Raegar finally gets a punishment from the Emperor, who he has betrayed.

Sources: Star Wars Insider #27, A Guide to the Star Wars Universe, The Star Wars Encyclopedia, and the cartoons themselves.