We meet again, General.
DISCLAIMER: I am not a legal adviser. This not to be considered legal advice. The opinions expressed by me do not necessarily represent the opinions of GameDev.net
Terms & Conditions always apply to everything in life - up to a point.
When you hire a contractor/freelancer, you are the customer (entering an agreement based on "good faith" i.e. that they abide by their advertisement/offer and in return, of satisfactory completion, the customer renumerates the other party upon the agreed price {price usually determining the level of quality to be expected}), and as a customer you are protected by the relevant state/national/international laws that apply (depending on the location of other the party/parties involved).
When it comes to intellectual-property/copyright etc., permission is needed to use an author's product of intellectual work (audio, music, artwork, characters, video {that includes computer-game-animation}, code etc.). An employer owns their employee's product of intellectual work. However, all non-employees (contractors, freelancers and volunteers) own their own work and give various consent/permissions of use. To completely own other people's product of intellectual work, requires their agreement.
So, when you release your game as a producer/publisher, your 'legal' concern should be that you've got the permission for every part of the game, to do so. (Nobody could have said that better themself - in my humble opinion.)
If you are the employer and all the work is entirely done by your employees only, then no worries, you own it all - it's yours to do as you wish. If not, if it's work done by other companies or non-employees (contractors/freelancers/volunteers) then you need to have had their permission. Permission with conditions is known as a license. Unreal Engine 4, for example, has a license https://www.unrealengine.com/eula, therefore, if you use their intellectual property, then they expect you to honor the terms & conditions that you agreed to in the license. If a person does not honor it (within the legal laws), and they find about it, and they think it's worth their time and money, they may take the matter to court and argue for example "The defendant agreed to pay 5% of every cent over $3,000 per quarter." And if you read carefully, that means even if a distributor took a cut, it wouldn't matter, that amount would still be considered as part of that $3,000 minimum, and you'd still have to pay 5% of any amount above $3,000 per quarter as if the distributer hadn't taken its cut at all. Ironically, there is an example in the actual license agreement that explained that better than I just did.
So, when you want original work done by a freelancer, you also want license (permission) from them to use it (or even better; ownership). That's the "legally covered" part. It's not that you couldn't write one up [a license agreement], it's that doing so is tediously boring. Then again, a simple email from the author stating in plain English that you have permission to use the work as you wish for free, for example, is technically, evidence of obtaining that permission. If you don't feel confident about writing T&Cs that covers all bases, then I'd consider having the correct lawyer, experienced in this sort of thing, help with the wording.
Just to reiterate: I am NOT a legal counsellor. This is NOT to be mistaken as legal advice. It is ONLY my layman opinion.
You probably already know about these freelance websites below (the list seems to never end). It might help you find the right animators for the right price.
https://www.fiverr.com/categories/video-animation/animated-characters-modeling/#layout=auto&page=1&ref=service_type%3Aanimated_3d_modelling
https://www.freelancer.com/info/how-it-works.php
http://www.guru.com/d/freelancers/c/design-art-multimedia/skill/3d-950/
https://www.freelanced.com/freelancers/3d-animation
https://www.ifreelance.com/find/providers/browse.aspx?c=4&sc=57
https://www.linkedin.com/title/3d-animation-freelance
https://www.upwork.com/hire/3d-animators/
Check each potential freelancer/contractor's reputation by checking their reviews whenever possible (as well as the reviewer), check their portfolio/work/list of clients (if they keep such a list and the dates if possible), and finally, interview them (actually talk with them).