I remember various knockoff TF's back in the day, including a couple 1/4 sized Roadbuster and Whirls, and then a very odd one...

There was a series of, I think, animals and such. The only one I clearly remember was a bat. Th legs would extend, the arms would slide out, the wings would fold, and then the chest would open and the bat head go inside, then close the chest, and you had a robot.

IIRC, most of the toy was black plastic, but the half of the wings that folded back were chromed plastic.

Does anyone remember this? And if so, do you know what toy or KO series this was?

I have the small size "Whirl". It must be noted that those two (from Tokuso Kihei Dorvack) came out in 3 official scales. The small scale were used to make KOs, the mid-range scale are model kits and the larger ones became TFs. I have the KOs for those, as seen here:

The middle one is not a Dorvack model, likely something old Macross or Mospeada. Ovelon Gazette and Tulcas are Dorvack toys and are the small versions. The middle one has the name Mugen Calibur, which was the name for Roadbuster's pre-tf incarnation.

sounds like convertors robat:
http://www.toyarchive.com/Convertors/Avarians.html
some of the many KO's using the convertor molds:
http://www.transformersontheshelf.com/KOBeastfighters.html

i have a 1/4 sized roadbuster i picked up, but i'm not sure what line it's from

Yeah, that's it exactly!!! (the Avarians)

I had the bat for sure it was my fav from the converters.  And I also had Rex.

hey thats where that weird random head came from.  back in febuary I went thur the parent attic cleaning out things from when i was a kid and found a box with the bird head of Calypso in it.
sweet, that's been bugging me for a while now

Looking at them, of the bird and insect ones I had  Rex, Robat, and Crawler (the other birds looked too goofy to me); I also had Chopper and Wheels from the Defenders; Nofka, Sunyak, and the SDF-1 from the Maladroids; and Cassette of the spies (Mom got it for me thinking it was the actual Transformers cassette, not knowing the "real" one came in a 2-pack...)

I also had a small red and yellow starship, about the same scale as the Convertors' SDF-1, that could transform. It went from robot mode to ship mode by basically splitting the legs in half, and folding half forward and half back... I dun remember what happened to the arms, but the yellow toes pointed forwards as the bow; the torso and head became the "bridge tower" of the ship. The 'bot' itself was mostly red, but had yellow gun turrets.

EDIT: Turns out it was a knockoff of "Iron Guard" from the anime Xabungle.