I would like to create a irregular shape in CSS like one below . I want to avoid putting image as background completely . Please help me in this regard..Thanks
This is not currently possible with CSS. The closest thing I know of is an experimental feature that lets you fit text into a shape, but it is as of yet very poorly supported.
If you load it in a browser that supports it, then the custom raven shape is set purely by CSS. Here's the webkit prefix style:
However, this is only to apply a shape to text. You could not currently style this shape, such as add a background color or a stroke. As Paolo suggests, you could use SVG to do that, which is supported inline for HTML5.
In addition then, you would have to experiment with box-shadows.
(this is, as @ckpepper02 points out, a question better suited for Stack Overflow, and you could start by searching for "css shapes" there. You will find some interesting stuff).