My new 1st level druid likes to use the spell "Aspect of the Wolf" for combat. Now the question arose whether he can use Handle Animal in wolf form to use the Attack trick on his riding dog companion.
There is no mention of language in the Handle Animal description.
"This task involves commanding an animal to perform a task or trick that it knows." PHB, p. 74
Thus my question: Can a druid in animal form use Handle Animal?
A character can give a simple verbal command, such as “Attack” or “Come,” as a free action, provided such a command is among the tricks the animal has learned.
DMG on animal companions, 206 (emphasis mine)
So, if you want your animal companion to perform a certain trick you have to speak the appropriate command, like in this case „attack!“.
As a DM, I would rule that a command could also be a distinct sound like whistling, snapping your fingers, clucking your tongue or making some guttural sound. But in any case it should be something your animal companion is able to hear and clearly recognize.
Since it’s rather hard to think of an acoustic signal that you can give in humanouid form as well as in animal form this won’t help you much.
There is some trigger (or several) and related reaction. Generally, you may pick whatever trigger you want your companion to recognize as a command. There should be no need in words... untill your companion never seen you transmuted into a wolf.
