Wow that last one is neat, at 1/1 its easy to kill and it requires another card to break it. That said, with Fastbond, Sylvan Safekeeper, Harrow, LD, etc. it becomes very powerful. I think it probably should just draw a card and not flip the card, this way it doesn't get around things like Underworld Dreams, Plagarize, etc.
The first creature is broken at GG, no doubt about it - especially in MP. I've seen Beast of Burden become a problem and this is so much better its not even funny, but that said Beast of Burden is far from broken.
At GG it can too easily become an attacking 3/3 (or a 4/4 with Rootwalla's) on turn 3 simply by building an aggro deck.
How about this, compare it to Squirrel Mob which is a 2/2 at 2GG. It only starts out as a 1/1, but its cheaper, untargetable, and activates on ALL creatures. And Squirrel Mob gets played in OBC (but still could have been a little better I feel).
He should cost 2GG I think or 3G. Don't do the 3/X thing, that takes away from the point of making a dangerous attacker and moves away from the initial flavor. Who wants to play with a green grower that wants to block?