Ohhhh.... good idea Animal31!  They would  be perfect!

I agree, pretty good for the first try.  I glue the lip sometimes, but I like to sew it in before the mouth place is put in place.  Sometimes it's more difficult and when I'm experimenting I usually glue it because I forget to sew it!

All the advice so far has been good.  I think the next one you make will be amazing!

Great effort.You are off to a good start. Removable eyes... a lot depends on your intended use. I like the plastic bolts idea . We just use pins, tape, and double sided tape when we can afford it... but we film, and  you only need things to stay on for a short time. For longer needs, a light hand stitching that you can quickly snip and pull out, works.

I think the little green man looks great and especially good for your first try!!
i agree with animal, the plastic nuts and bolts idea is something i have used myself in the past to great success, they are also used for attaching registration plated on cars in the UK, so they are everywhere!!
i have also used neodymium magnets to make removable facial features on puppets, they have to be in both the head of the puppet and the facial feature, but they are fantastic and really 'pull' the feature onto the face and Ive never had any space left over, but you could also try making the eyes so that they follow the curve you are trying to add them onto and then even the Velcro method would work, you just have to experiment a little more, maybe even try putting some felt onto the face where you want the eyes (simply place it here) then apply a light coat of PVA glue (Elmer's for you folks in the USA) to the felt allowing the weight of it to conform to the curve of the face (making sure you don't get any on the face) then let it dry, and voila you have the backing to the eyes that fits perfectly to the face, you can then build the eyes onto the felt and its a custom fit!!
i hope that all makes sense, its just a case of experimentation.
Ben.

Jeezbo, how do you use the plastic bolts? Do they pass right through the puppet head? How do you get the  nut on? It sounds interesting. Any pics of their use?  Concerning the felt and PVA glue(good idea), you could put a bit of plastic bag under the felt while you glue it,so the glue does not stick to the puppet face, but it will not interfere in taking the shape of the head. I am using the PVA and cloth idea for eyelashes now.

Thanks for all the comments and suggestions. I'm going to try the plastic bolt idea that some of you have suggested. I liked the idea of making a flap in the fabric for the eye to sit inside but I'm horrible at cutting and sewing fabrics so I'm sure if I tried that I would make it look all clumsy and jagged.

This was just my prototype and I learned a lot building him even from the mistakes I made. I think the real one will be a shade of gray so he looks more like an alien and less like a frog or lizard. Besides I may do some green screen work with him so if I leave him green he'll disappear.

I'm experimenting with some pointy ears. Once I have his body and costume done that should make him look a bit more alien. I'll be sure to add an update and show how I do the eyes if I can get it to work. Thanks again for all the comments and suggestions. I have a whole cast of characters to build so I'm sure I'll have a lot more questions.

The one big rule I've learned from puppetry: practice, practice, practice. You get better over time!

Perfect symetry is overrated. Lopsided has unique character.  Though I do agree the pupils are usually perfect circles.  I used vinyl sticky letter "o" as a guide to color in a nice round iris stencil. Your best sewing tool is that seam ripper, don't be afraid to rip it out and try again if you are not happy with the first go.

ha, ha, ha Sanil.. your best sewing tool is that seam ripper. HOW TRUE.

Sorry Snail (hit the wrong button and posted before I checked the spelling) S.N.A.I.L   . there , got it. But so true. That's the great thing about stitching. You can unstitch it all , and restitch again