Custom Mobs not spawning

So i made a mob and it isnt spawning after recompiling over and over again. There is no errors with the recompiling
i think there is a problem with the texture anyone now how i upload the pic like wat size it has to be

If you use the mod "Singleplayer Commands" you can spawn your mob, if you do that and see the mob there is an error with the spawning in our code but if you don't see the mob then you probably have a error with the texture. It is good to spawn the mob in a little box so you can kill it or try to hit it if you don't see it.

Sorry for my bad English.