Early Calvin
There are two types of Early Calvin, Marvin and Calvin with shaggy hair. They were both made previous to when the Calvin and Hobbes comic strip began. There is an additional semi-type, where shaggy-haired Calvin (unnamed) was featured in another Early Comic Strip by Bill Watterson, before Calvin and Hobbes was released.
Meanwhile Hobbes has only ever gone by Hobbes. Even previous to the release of Calvin and Hobbes.
Marvin was an early concept for Calvin. He was just like Calvin except that he had much longer, shaggier hair. The name was eventually changed to Calvin, then later Bill Watterson removed the long hair as he felt it looked ridiculous for such long hair to be covering the boy's eyes.
Few strips exist with Marvin. One was where he's in his Spaceman Spiff outfit in class and gets sent to the headmaster. A second strip had Marvin eating dinner with his parents and requesting him to take some to Hobbes. Marvin's father (an older looking version of the later design Calvin's father) is unaware of Hobbes, to which Calvin's mother (Also a more older looking version of Calvin's mother) explains that Hobbes is an imaginary friend and chalks up Marvin's request to desiring extra helpings. Marvin then brings the food to Hobbes, who said the request for wine was denied. A third strip that did get completely revamped was where Marvin sneaks out of his house at three in the morning, going to a nearby payphone to ask his father "Do you know where I am?".
These strips are shown in the book, "Exploring Calvin and Hobbes: An Exhibition Catalogue"
Bill Watterson eventually ditched the Marvin name after (2?) strips but kept the longer hair design temporarily, before removing it after (3?) strips:
Gallery
Marvin Comic Strips
Calvin with Shaggy Comic Strips
Bill Watterson dated these circa 1984.
Calvin (Other Bill Watterson Comic)
Calvin was featured as a random character in an old Bill Watterson comic, previous to the release of Calvin and Hobbes.
