I thought Snoopy's brother was named Spike? *shrugs* Maybe Snoop has an extended family. Same for Woodstock, as there's been times where there's been more than one type of Woodstock-esque bird around.
What sold me on Linus was how he could switch from drastically upset (often, this occurs when his security blanket is not with him), to philosophical (see his stance on [what truly is the meaning of Christmas [and to be forewarned, it does have a religious connotation]), to giddy little kid (in regards to The Great Pumpkin), and to a tough guy (whenever one of his friends is in trouble, it is often Linus to the rescue).