Welcome to Gaia! ::

As some one who is quite O.C.D. about what they draw, I notice that you (and, for this instance, your friend) have the same problem as I do with human feet and shoes... I also noticed that the muzzle looks a tad off (probably the attaching of the muzzle line to the neck) on #1 but it isn't much to complain about, from the angle of the picture in #2, the neck looks too stained for a more relaxed pose like the one he's in (once again, it isn't much to complain about), the creatures were done well but you added the horns after drawing the head which takes away a bit from the dragons and the head and the tracks kid, in #3 and #5, were done very well.

So, as an over all recap, work on feet, don't do feature creep (the horns), and good job.