Manga vs. Anime
        The Anime of Claymore is the first eleven volumes of the Manga animated. However, there         are a lot of differences between the two, especially as you get to the later episodes of the         Anime. There's a lot of argument over why these changes took place and if that means         there'll be a second season of the Anime or not, but that's probably a discussion better left         to the forums. I personally believe that the changes took place due to the fact that the         Manga wasn't finished (and still isn't) when they created the Anime, so they didn't want to         create an ending for the Anime that would completely end the series. Sure, the Anime ends         in a way that many complain ruins the rest of the Manga's story and they'd never be able         to pick it up again, but with everyone parting ways in the end and promising to meet up         again in the future, I'm sure they'll figure something out if they really want to.

If you can think of any more differences I might have missed, please email them to me!

Manga:
Irene, the rank 3 Claymore during Teresa's time who uses the Quick Sword technique, is actually named Ilena in the Manga.
Anime:
Irene isn't even named Irene in the subbed or dubbed versions of the Anime. Her name is Ilena, pronounced as Ee-lay-nah or Ee-ray-nah if you prefer (there is no "L" in the Japanese language, which is why "R" and "L" are often exchanged when it comes to spelling in English, and in Japanese "I" is pronounced as "E" like in see). So, I suppose people saw her name spelled as Irena and thought they were saying Irene instead of actually sounding out the name as it would be pronounced in Japanese (or actually listening to the Anime in English or Japanese). The proper spelling into English for her name should be Ilena (or Irena if you prefer the "R" sound to the "L"). Even spelling it as Elana would be more correct than Irene.

Manga:
There is a friendly battle between Clare and Flora because Flora wants to test her Windcutter against Clare's Quick Sword.
Anime:
Flora offers the challenge of the friendly duel to Clare, but Jean intervenes and the fight does not occur.

Anime:
Raki discovers Priscilla feasting on a Human's entrails inside a cave in the North and Easley appears to explain Priscilla's past as a Claymore and how she now suffers as this creature.
Manga:
Raki never suspects either Easley or Priscilla of being anything other than Human and he never actually sees Priscilla eating a Human.

Anime:
Raki leaves Priscilla and Easley to go into Pieta and look for Clare after a passing traveler from the city explains the situation there and the Claymores in the town.
Manga:
This does not happen at all in the Manga and Raki continues to travel along unsuspectingly with Easley and Priscilla to the South.

Anime:
Clare fights and defeats Rigaldo after awakening her legs. Raki also reaches the city and finds Miria along with the other injured Claymores. He witnesses the fight between Clare and Rigaldo. Later, when Clare goes after Priscilla, she awakens further and her arms transform.
Manga:
During her fight with Rigaldo, Clare awakens her arms as well and not just her legs. It is with her arms and special diamond-shaped appendages that she tears Rigaldo to pieces. Raki does not appear at all since he continues to travel with Easley and Priscilla.

Anime:
After fighting Rigaldo, Clare begs Helen for death as she feels herself slipping away and beginning to fully awaken. Sensing Clare's Yoki and essentially being reminded of Teresa due to the fact that Clare shares Teresa's power, Priscilla's memories begin to return to her and she awakens. Clare then senses Priscilla's Yoki and takes off to find her before Helen has a chance to act. Jean and Raki follow after Clare while Miria and the others are approached by Galatea who points out Clare's whereabouts by a volcano to them. After a brief fight with Priscilla who loses her wings and reverts to her Human form, Clare begins to slip further and begs for death. Jean attempts to help her and is impaled by Clare's diamond-like appendages. Jean then uses the last of her Yoki to help Clare revert and then dies. Jean is then buried and everyone parts ways, vowing to meet again.
Manga:
Clare still begs for Helen to kill her after her fight with Rigaldo as she begins to fully awaken, however, before Helen can do anything, the mortally wounded Jean appears and approaches Clare. Jean is impaled by Clare's appendages and Jean uses the last of her Yoki to change Clare back to normal. Jean then dies and Miria, along with the remaining survivors, gather around Clare. The Awakened Beings, now without their captain Rigaldo, return to finish off the Claymores. The chapter ends with a cliffhanger showing the seven remaining Claymores squaring off with a lot of Awakened Beings.