In any essay, the conclusion is a rewording and summarizing of the main points of an essay.  After all, what an essay is composed up is basically a general statement with opinions, or points about the statement supported with reasons and examples.  Since the word essay (derived from French) means to try, the writer tries to prove his/her point.  In writing a paragraph, the same principle applies, just in a lesser dimension.

So, once the body of the essay/paragraph is written and the opinions/points are supported/proved, the writer looks back at them and writes a summary.  In other words, the writer tells the reader what he/she has just told them.

Using one of the strong examples of the post above that the lion is important to the balance of nature in Africa, let's suppose you have made the point that the lion kills the weak or sickly of a herd which helps to strengthen the herds, ensuring that future generations will survive.  Without the lion's killings, the herd's weak would reproduce more weak;  then, the herd would all become weak, and eventually die off.  Now, in the conclusion, you will summarize this point by writing that the lion ensures that only the strong of a herd surivive for future generations.

For more help see the site below which gives directives on writing a conclusion.

If you are discussing how the lion needs to continue to populate and be allowed to live its life, a good concluding sentence might be to discuss this need in more detail.  For example, "The lion is extremely important and its way of life should not be hampered by humans, but actually helped by them."  Something along these lines might be good.  Again, as the previous post identified, it is a challenge to help with conclusions without fully understanding what is being argued throughout the paper.  If you are presenting a paper that offers straight analysis about the lion and its habitat, your concluding thoughts might lie in discussing how important the lion is to our world might be another way to close your work.  In recognizing the film, "The Lion King," maybe closing with something about "the circle of life" might be humorous and insightful.  My guess is that if this is something you want to do, it should probably have had some prior introduction or discussion in the paper to a certain extent in order to make its reference in the conclusion a meaningful one.

It is not possible for someone to write a conclusion for you without any information about what you are saying in your essay.  In other words, we would need to know what you have said about lions in order for us to be able to help you.

What you should do is figure out what the main points of your essay are.  That is what you should repeat in your conclusion.  You need to use the conclusion to emphasize the most important points that you have made in the rest of your essay.