Basil Blanchard is one the more known students in the Slytherin house. He's also a halfblood. His mother was a very popular and successful student at the Beauxbatons Academy of Magic and his father, while a mere muggle, is an acclaimed stage actor. Now, most people would probably be quite proud of having well-known parents. Not Basil. He's ashamed of his family. More specifically, he's ashamed of his halfblood status. Basil's still under the impression that blood status is all that matters in the Slytherin house. He's afraid of being bullied and ridiculed, and he constantly tries to act like a "real" Slytherin in order to not get targeted. This means that Basil will often tease and snark at anyone who isn't a fellow serpent. (Needless to say, Basil has a very stereotypical view of the Slytherin house) This has earned him some recognition from the less than pleasant individuals in the house, who appreciate his "bluntness" and his "don't-give-a-crap" attitude. However, That's not who Basil truly is. It's all an act. 

Now, performing the same act for five years does leave marks, and Basil has become more cold and insensitive during his years at the wizarding school. He's no longer the starry-eyed and naive pup that eagerly walked into the Entrance Hall five years ago. His new found "friends" has sadly influenced both the way he acts and, to some degree, the way he thinks.
He isn't completely without empathy though. If a fellow Slytherin is in trouble, he won't hesitate to help them. He might even, on the rare occasion, aid someone from the other houses... as long as there are no other Slytherins around.

Basil's a clever and quite cunning individual, and he's more than willing to break the rules if it benefits him. To him, rules are more like guidelines than something set in stone. 

Many people, even some Slytherins, believe Basil is difficult to approach. However, those who are willing spend some time with him away from the classrooms may get a glimpse of the real Basil: the creative and surprisingly intelligent young dog that possesses an admirable degree of determination. 

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