Hmm
5 Animal Frolics was indeed founded by Hua To, and is considered by many to be the original Dao Yin set that precursored all other qi gongs.
However I think its probably fair to say that that was the first recorded mention of a qi gong set.
Qi has been around since the dawn of time and people's recognition of it under another name prehaps must of been known prior to Hua To aswell.
The 5 animal frolics depicts and exhibits 5 different qualities represented by 5 different animal based qualities.
From the health prespective they also co-ordinate with five main sets of organ functionality too, so it is a whole body exercise. For example the Bear qi-gong set emphasizes the Liver and the Crane the Lungs and Deer form is most famous for it Kidney strengthening aspects.
I myself have not learnt the entire sets of all 5 animals and mostly just practice Deer and Crane sets for their specific results.
Longer forms however like a Taiji Long set has the equivalent effect of doing all the animal forms together. So, as Taiji is a qi-gong too, it is down to preference as to what one wants to practice and develop.
I have studied a few qi-gongs but my heart remains with Yang style Taiji.
" Don't confuse yourself with someone who has something to say " - The Fall
" I do not like your tone/ It has ephemeral whingeing aspects " - The Fall
" There are twelve people in the world/ The rest are paste " - Mark E Smith