だらけ is a 接尾後（せつびご） (suffix) that is used in Japanese to express when one thing is ‘covered in’, or ‘filled with’ another thing.
だらけ will be attached to the end of nouns, before (sometimes) being followed by the 格助詞（かくじょし） (case marking particle) の and a second noun. The second noun is frequently omitted if the place or thing that is ‘covered in’ something is obvious.
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パンケーキの裏側（うらがわ）が穴（あな）だらけで気持（きも）ち悪（わる）い。
The underside of this pancake is covered in holes so it is gross.
この公園（こうえん）はゴミだらけだからこどもを連（つ）れて来（き）たくない。
This park is covered in garbage, so I don't want to bring my kids here.
傷（きず）だらけの車（くるま）に乗（の）っているのを見（み）られたくないからいつも妻（つま）の車（くるま）に乗（の）ってる。
I don't want someone to see me drive a car covered in scratches, so I always drive my wife's car.
泥（どろ）だらけの服（ふく）を洗濯機（せんたっき）にいれないで！
Don't put mud-covered shirts in the washing machine!
だらけ is primarily used to express things that exist in a ‘scattered’ state (like stars in the sky). Due to this, it will not sound natural when used to describe a thing that is ‘covered in’ something that is not scattered in some way.
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壁（かべ）をしろだらけに塗（ぬ）ってください。
Please cover my wall with white paint. (Unnatural, unless the speaker specifically wanted paint speckled, rather than covering the wall)
血（ち）だらけのシャツをクリーニングに出（だ）した。
I took my blood-covered shirt to the dry cleaner. (Natural, as blood drops may be scattered)