...Even though you are new, please show at least some effort other than just showing an outlined animation. Also even before you post this, why not look around at other threads that have had the same inquery, this way time could be saved.
Anyway, in regards to the animation, the character puts to much effort into his arms. Either arm looks like it's only 3 pixels away from smacking him in the face, which isn't really normal. So in other words, just tone down the effort exerted into the arm movement, detail the entire thing, and then ask for critique.
Next on your more recent additions the walking for the male character is way to exaggerated and it seems like your character is doing a head bob to some unheard music, either that or tripping. So tone down the leg strife, redo the overal posture, and fix the hands.
Finally onto your lizard, you need to add more detail overall especially if your trying to depict a reptilian. You will need to add scales in general if that was your goal. Now in regards to the animation, well for one the overall body conception with the breathing is a little exaggerated, and the arms realy shouldn't move unless it's truly exhausted. Then on the tail, it breaks all the rules of anatomy by only having that portion of the tail move. Usually, except in rare cases with snakes and worms, everything moves via a joint, which would be the tail bone, or cartiledge of that lizard tail. So even if you fantasied that it could move it's tail because of it's human-cross breed structure, there still couldn't be a frank possibility that it could do that form of movement unless you perceived that there are joints along the entire tail which would alas make it a bone-tier movement which would limit the mobility of the tail, and cause it only to curl in one direction and not two without breaking the joints unless there was the case that it was double-jointed. So I would suggest moving the entire tail from side to side via the base to add the final tinge of realism to this peice.