The giraffe's ear is falling off .
or The giraffe's ear has fallen off .
You can also say: The giraffe's ear is coming off . or The giraffe's ear has come off .
To be accurate, you wouldn't say something has fallen off (or come off ) unless it was completely separated from whatever it was attached to.
But kids are not always as precise with their language.
(Edit):
Also (as per BruceWayne's comment) The giraffe's ear fell off .
The giraffe's ear came off .
ell.stackexchange.com/users/42184/Andrew
The ear on the giraffe is loose .
Or, in the possessive form, The giraffe's ear is loose .
Describing the attachment, or lack thereof, between the two components.
You can also use the word detaching , but it has other connotations if not entirely unsuitable denotation.
ell.stackexchange.com/users/50680/can-ned_food
The giraffe's ear has not fallen off, it is still stuck, precariously, onto its head.
If it had fallen off it would have landed on the floor.
Perhaps the child meant to say it is about to fall off .
another way of describing this endearing zoological feature is to say: The giraffe's ear is lopsided
Oxford Dictionaries state
that lopsided means (emphasis mine):
“ With one side lower or smaller than the other.”
synonyms include: unsymmetrical, uneven, unevenly balanced, unbalanced, off-balance, off-centre, unequal, askew, skew, skewed, squint, tilted, tilting, crooked, sloping, slanted, aslant, one-sided, out of true, out of line, to one side, awry.
ell.stackexchange.com/users/1694/Mari-Lou A
Does this help?
One of the ears of my giraffe wall sticker has fallen off.
Or if you want to say only part of the ear has fallen off: Part of one of the ears of my giraffe wall sticker has fallen off.
ell.stackexchange.com/users/63258/Livrecache
When stickers, paint, wallpaper, posters, and other such flat things that are stuck to walls come partially unstuck, native English speakers would usually say that they are peeling off the wall.
The verb fall off is reserved for when the object has come completely unstuck and is now on the floor/ground below where it used to be.
(In the case of paint, wallpaper, and other things that are intended to cover the entire wall, we say "peeling off" even when there are bits on the floor, because usually the entire wall hasn't lost its covering.)
In your case, we would say "the giraffe's ear has peeled off the wall" but "the giraffe sticker is peeling off the wall".
Also, adult native speakers would only say that the ear has fallen off if it has detached from the rest of the sticker .
The entire sticker can fall off the wall, but the ear by itself can't fall off without either taking the rest of the sticker with it, or tearing away.
But we might say that the ear has fallen down if we wanted to emphasize its new position rather than how it got that way (peeling off the wall).
ell.stackexchange.com/users/2823/zwol
I like the suggestion of
The giraffe's ear is coming off .
In this case I would stick with the present continuous (not came off) because the ear isn't all the way off the wall: it's still attached, either by part of the ear or by the rest of the giraffe.
If it eventually tears away from the rest of the giraffe so it's completely gone then came off would be more appropriate.
If you wanted to be more specific about the fact that this is a sticker , you could also use the verb peel , again in the present continuous: The giraffe's ear is peeling off (the wall).
Personally, because it's a sticker, I would probably say The giraffe's ear has come unstuck .
Or The giraffe's ear is coming unstuck .
With "come unstuck" you can use the present perfect, because the unsticking of the ear started in the past, and still is in effect now.
You could also use the present continuous because only part of the ear is unstuck, but more might be losing its sticky as we speak.
The first is better if you want to emphasize that the ear is detached from the wall, and the second is better if you want to emphasize that it's only part of the ear.
I wouldn't really expect a young child to use "come unstuck", though, especially in the perfect form.
(It might sound especially felicitous to me because of the famous line " Listen: Billy Pilgrim has come unstuck in time. " )
A more casual alternative that would probably work for a child is to use the verb unstick : The giraffe's ear is unsticking (from the wall).
ell.stackexchange.com/users/37569/1006a
"The giraffe ear is  fell off ."   my son told me.  One of the ear of giraffe wall sticker is fell off.  What do we say for this? The rest (giraffe's body) is still sticking on the wall.  Only part of its ear is dropping.
The giraffe ear is fell off
ell.stackexchange.com
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ell.stackexchange.com/questions/144144
ell.stackexchange.com/users/45751/JJ12345
The giraffe's ear is  loose The ear on the giraffe is loose.
The ear on the giraffe is loose. Or, in the possessive form,   The giraffe's ear is  loose. Describing the attachment, or lack thereof, between the two components. You can also use the word  detaching , but it has other connotations if not entirely unsuitable denotation.