I have got pictures of Sienna as a baby, must scan them at some point, she is really very chunky, but that's due to not having made the height she was meant to. She's half & half & looked like a scruffy pony when she was a baby.
This is my 14yo IDxTB. He's by Banks Fee Daniel (the ID bit!), out of a TB mare (polo pony I think). Am told he was tiny, I mean really tiny, when he was young, but then just kept on growing..he's now just over 17hh!