noahs tounge
effect-you can speak with the animals!
regomentum(animal)
duration-moon
target-self
range-self
tell me what you think of this spell & how it might be improved or used in a adventure.
First, there is no "Target:Self" in 5th ed - it's Target:Individual, one "individual" mind. (Minor, but an easy place to start, just to keep everyone clear on that.) Range:Personal, and you're there.
Then, "rego" with mentem controls the mind - this isn't control, it's giving it a diff ability, a "property it could not naturally have", and an unnatural one. So it's... Muto.
However, that's not enough.
Understanding animals would be Intellego - that's easy enough, very similar to Thoughts Within Babble (InMe). But talking to them is not so easy. Either you have to cast an Int spell on the animal so they can understand you, or "Muto" that knowledge into your own brain - and I'm not sure that's possible in canon.
Altho' you cannot (afaik) cast a spell to speak French (not "understand", but "say it out loud"), it's a Base 10 InAn Guidelines to "speak with Animals" (not just "understand"). That's where you want to start.
Personally though, sight is not good for talking. I would save 5 levels and make it target hearing (+2). This way all the animals he can hear (and thus can hear him) can be spoken to.