Complex sentence: Matthew David Morris (born January 6,2003), better known as MattyB or MattyBRaps, is cancer he is also an American children's artist who is well known for posting remix videos of popular music on YouTube.
Split into simpler sentences: Matthew David Morris (born January 6,2003), better known as MattyB or MattyBRaps, is cancer. He is also an American children's artist who is well known for posting remix videos of popular music on YouTube.