Tens of millions of years.   Coal is a fossil fuel created from the remains of plants that lived  and died about 100 to 400 million years ago when parts of the earth  we â¦ re covered with huge swampy forests. Coal is classified as a  nonrenewable energy source because it takes millions of years to  form.
New Scooby episodes, in the original Scooby-Doo, Where Are You! format, were produced for each of these three seasons. Four of these episodes featured Scooby's dim-witted country cousin, Scooby-Dum, as a semi-regular character.
1 From Scooby-Doo on Zombie Island to Scooby-Doo and the Cyber Chase, she had blue irises; interestingly, when she hypnotized was in the Scooby-Doo, Where Are You! episode, Bedlam in the Big Top, she had blue irises in a close-up. 2  In the opening sequence of Scooby-Doo! 3  Abracadabra-Doo, she had green pupils.