Mythical beasts qualify as magical animals according to RoP:M and so work according to ArM5. Based on Hope's familiar, I think you have a fair amount of flexibility. Of course, it's Might cannot be really high.
Considering we have a xenomorph and an undead...creature of some kind, and possibly a homunculus or Groot, I'd say fantastic beasts are fair game familiar-wise.
How best should I make a homonculus familiar? Should I use the same hand-waving that we use for a regular familiar and just make it up, figuring on a season to craft the spell rather than a season to find the familiar? (I could even take a Flaw "Magical Object Companion" if you like.) I must admit I'm bewildered (and discouraged) at the idea of having to make one or more level 50 rituals to craft a familiar.
(Also, now you have me wanting to name my familiar Groot if I manage to make this work. 
)
There is stuff about homunculi in RoP:F. You might start there.
I knew I was going to get in trouble by using homunculus, since it's a term of art in ArM5.
I am not looking to create a homunculus wizard as described in RoP:F. I do not want the major story flaw that externalizes the gift, nor do I want a Faerie homunculus that I must hide from the world. (Not to mention the fact that a homunculus wizard cannot have a familiar or a talisman.)
What I want, if possible, is an animated magical object (a stick person) as a familiar. I was really using the term homunculus in its generic sense rather than its specific sense as written in RoP:F.
I suppose I really should have said that I want a Little Wooden Boy[sup]1[/sup] familiar.
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[sup]1[/sup] - for those of you familiar with the Tick.
Wizard's Motion
ReCo 25
R: Per, D: Sun, T: Ind
The caster can move freely in sea or air at the speed of a fast horse/fish – a maximum of about forty miles an hour. Fancy maneuvers may require a Finesse roll.
(Base 15 - Move a target quickly in any direction you please, +2 Sun)
Phantasmal Murder of Crows CrIm20
Creates an illusion of 100 crows bursting out of the caster. The birds will then swarm/circle the area of the caster for 1 minute than scatter in all directions. This is meant as an impressive way of hiding what the caster is doing. Corvus could change into a Crow and scatter with the illusion or use the confusion for other matters. The birds stay in a room sized area and make a lot of noise.
R:voice D: Diameter, T: group
(Base 3 ( sight, sound, touch) Voice +2, Diameter +1, group +2)
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Not sure of the number of crows. Group give it the mass of 10 ponies (base individual CrAn) which are size +1. A crow is size -4. Does the calculation double the number 5x based on the size difference between +1 and minus 5? If so it will be a spectacular large number of crows.
Each Three size ranks difference is ten times the mass, I think. That's easily 1000 crows, probably more.
It is suppose to be spectacular 
Wait until they are real crows/ravens :mrgreen:
No. For example, if you use T: Group, you cannot affect 20 normal-sized humans even though the individuals could be Size +1. That's the cap for each individual, not always the size of the individual. So you could think of it as T: Group, +1 size for 100 individual illusions. (See below for an alternative.)
These crows are not stationary, right? They're supposed to fly around and seem like real crows? Don't forget the +1 moving image. (It would be +2 to move under your control, but I don't think you want that.)
But it's probably better to think of it as a single complex illusion (the murder is the illusion, not each crow). This doesn't get you past the movement issue and adds a new one, but it deals well with the Group+1. An individual of Imaginem is an image the size of a person, which I think is accepted as up to Size +1. An elephant is Size +4. That's a small but not tiny room, which may be big enough for you. So you might be able to get away with T: Individual, +1 size. But now you're talking about an illusion with many different parts, which typically adds +1 magnitude for intricacy. If this size (a room about as big as an elephant) is what you're thinking, then you can pull it off at the level you planned using T: Individual, +1 size, +1 intricacy, +1 moving.
But now I'll do better for you: R: Touch! This illusion bursts from the caster, so it must affect the image of the region the caster is touching. That drops things a magnitude. That means you could keep Group+1 if you want 100 if them and still have it be CrIm20. Or you could do the complex Individual+1 for CrIm15. Or you could go with a larger Individual: Individual+2 for CrIm20, handling a region as big as 10 elephants.
Regardless, there is a great cool factor here! Nice spell!
As a basic idea, this seems to work well. Who really cares what you're moving through, since you're just moving through fluid in a direction. However, I think flying through branches at 40 mph would cause problems. Well, moving through water at such speeds is pretty bad. I've traveled through water at slower but significant speeds, even with my eyes open. I don't recommend it. I would estimate on one flip my head was probably moving closer to 30 mph through the water when my eyes were open (it was supposed to be in the air, but I took off from the wake poorly). Both eyelids got flipped from the pressure of the water on them. As I was in pain and couldn't open my eyes, they pulled me into the boat after and were worried when they saw blood coming out of my eyes when I tried to open them. The solution ended up being simple: pull my eyelids away from my eyes so the eyelashes could flip back outward instead of being on the inside. The point is, you're not going to do well moving through water at those speeds. I would think you would need +1 magnitude to have your body be more resistant to the fluids. I'm not sure, but you might need an Aquam requisite (included in that +1 magnitude, not another magnitude). Is it essentially a ward against fluid pressure (ReAq as part of it), or is your body adapting (which might need Muto?)? For air alone we know you're OK at speeds higher than this. But if we get closer to 200 mph (+1 magnitude probably), then you'll start to have some issues with the air, too.
Of course as your example shows, being able to go at speed is not the same as it being a good idea to go speed. Nothing stopped you from going at 30 mph; you just had some bad effects from doing it. I'm assuming that was a boat involved that was going at 30 mph. That boat could have moved you at 5 mph or 45 mph. Nothing prevented it from doing so. Now, the frailties of human body make it a bad idea to be dragged along behind about at 45 mph. But that doesn't affect the capability of the boat.
In the current case, I would argue that the spell should be just as effective moving through water as through air for the reasons you note. Now, it might not be wise to use it at speed. Heck, it might be downright dangerous to do so without some additional magical protection. But the spell could be used to go 5 mph without any danger.
My take is that there shouldn't be Aquam requisites to ward against fluid pressure. Rather, there might be the requirement for something like a MuCo(An) spell to make the caster's body more resilient to travel through water (like a fish or porpoise)if he or she is going to go at any high speed. That's one way around the problem.
FORTIFIED EYES OF THE DOLPHIN
MuCo 5
R: Touch, D: Sun, T: Ind
Req: Animal
The target gains the eyes of a dolphin, which allow him or her to travel underwater at high speed without damaging them.
(Base 2, +1 Touch, +2 Sun, requisite free)
FORTIFIED EYES OF THE FALCON
MuCo 5
R: Touch, D: Sun, T: Ind
Req: Animal
The target gains the eyes of a falcon, which allow him or her to travel in the air at high speed without damaging them.
(Base 2, +1 Touch, +2 Sun, requisite free)
Now, that being said, there may well be something to be said for an Aq requirement (or an Au requirement for air travel - you try looking into the wind as you fly at 40 miles an hour) to protect against the elements as an alternate possibility. In fact, as I think about it, that's probably a more elegant solution, though one that makes it much harder spell to obtain (perhaps rightly so).
Yes, being pulled probably a little shy of 20 mph by a boat (don't need to be fast on a kneeboard). The extra speed was partly from cutting across the wake and partly because in a back roll the lowest point of my body (my head when half-way around) is moving the fastest to have the rotation work.
I agree. You don't have to go that fast and should really avoid it.
Yes, MuCo(An) is a very good way to solve the issue with another spell. And, of course, if you're under for long there is the whole breathing issue. I do think Rego could do it as well. Probably better as you suggested rather than making this spell even harder.
You'll be fine in the air at 40 mph. I go a lot faster than that on a slalom ski when cutting across the wake.
So is that number only with Imaginium because the illusion does not have mass? I look at Curse of the Ravious Hoard which is a CrAn spell that describes group of insects the mass of 100 pigs. And Group uses the mass of 10 individuals vs just 10 individuals
Imaginem doesn't use mass. Seen the last paragraph of ArM5 p.143.
Looks like I'm wrong about Group, though. I just reread the general rules. Apparently a normal T: Group Corpus spell really could affect 20 normal-size people. Wow! For how long have I been doing that wrong!
So... Ten crow images in a person-sized image seems reasonable. Go to Group for 100 crow images. That works. You'll still need +1 for moving image. But you can drop Voice to Touch to balance that increase.
I would still guess 10 normal sized humans as that is the individual for Corpus. But I would also guess you could play with the number a bit.
It is why I was trying to roughly figure the difference between (Now) size 0 and size -4. Which 100 gets in the ballpark
What do you make of pg 62 of HoH:S Group: Sufficient species to create and maintain a life size illusion of a group of humans or smaller objects.
I wish it were more plain that Group worked differently with Imaginem...or I am just not finding it. I could pose the question to the general forum.
Individual for Corpus is as large as Size +1, just like for Animal.
It works the same way, it's just not based on mass. For images it's based on volume. But via density that becomes roughly equivalent. But if they had gone with mass or weight someone might have said an image weighs nothing so they could make as large an image as desired as an Individual. This way, based on volume, there are easier sizes to work with. That bit you mention in HoH:S is saying the same thing: size, not weight or mass.
As I said after fixing my thoughts on Group, I think the spell is right. I would just change it to R: Touch and include +1 changing image.
REVISIED:
Phantasmal Murder of Crows CrIm20
Creates an illusion of 100 crows bursting out of the caster. The birds will then swarm/circle the area of the caster for 1 minute than scatter in all directions. This is meant as an impressive way of hiding what the caster is doing. Corvus could change into a Crow and scatter with the illusion or use the confusion for other matters. The birds stay in a room sized area and make a lot of noise before scattering. The caster's view outside the illusion is as hampered as someone's view into the illusion.
R:touchD: Diameter, T: group
(Base 3 ( sight, sound, touch) touch +1, Diameter +1, group +2, +1 Changing image)
Enslave the Fickle Heart [ReMe20]
[tab][/tab]R: Eye, D: Concentration, T: Individual
[tab][/tab]For the duration the target of the spell is devoted to the caster. While this does not provide mental control, the target will follow most non-suicidal requests.
[tab][/tab](Base 10, +1 Eye, +1 Concentration)
Would that be a CrMe Base 4? Placing an emotion in the head?