On your old school fusions: Croconaw/Typhlosion i would say is too basic, but then i would be implying that it's possible to add more to the sprite. Highlights could be returned to the right leg and foot as well as areas around the fire.
Not much you need to do for diggachu... nice!
Smearglebuzz: One thing is really interesting me, where are it arms even coming from?! It tends to give your sprites better definition when you use outline colors that go with the filled area; for instance on the tail brush, most of it is dark grey so the outlined should be black instead of the dark yellow. Make sense?
Cubone/Growlithe and Nidoran/Growlithe: both are pretty simple and mostly just recolors so i can't really expand on them, sorry about that.
Raichatata: Ok, alot of experienced spriters will tell you not to copy and paste, even though they do it. Generally they just say "scratch it" however, you can use scratching abilities to touch up the c+p parts. The shading in his wiskers doesn't make sense with the shading on his head. The face could use a lot more highlights, save the shadow area for under the chin. The inner ear could be smoothed out outline-wise, for which the scratching i referred to earlier will come in handy. For the record i think the sprite would be most excellent with ratata's style tail.
Shinx/Growlithe: again nothing wrong, it's very simple.
Vulpix/Growlithe: The shading in its tail shouldn't be that dark given the angle and light source, you need to up the tint altogether on the tail.
Liek the prinplup egg..
Your dinosaurmon fusion has well done shading, i only suggest you give some of the spikes (specifically the head spikes) a shadow, to give them the sense that they exist.
Then use the same dark shade you make the shadow with as the bottom outline of the spikes. It will make the spikes look connected to the body.
Your smoking saur: overall, not very problematic. i applaud you, i like this one.
Volkoffywag: < idunno. The feet seem out of place, which makes it look very off balance. move the left one lefter. that is all.
Hopefully some of this helps you. I also didn't mean for any of it to sound harsh if it did, i apologize. otherwise....
Sprite on!