that requires a minimum of 30 terms in the Fourier expansion. This Demonstration shows that you can get fairly close with 15 (five more if you want your elephant to have an eye).

The larger question addresses how far you should go to "back into" a theory from data. The plot of the data shows that it has little correlation. Indeed, Pearson's correlation coefficient for this data is very small. Yet with adequate computing power a set of equations can be found. The message becomes: if you want this elephant to have feathers, Mathematica can include them in the fit. Have you have found a theory in your data? No. Is your client impressed? Perhaps, if your client is a cartoon company.