Pieck finger looks very serious and I am so hype what it will happen next. I don't read manga I just stick with the anime.
Facts about the cart titan. Cart titan was used for warfare sending supplies and helping it's allies to travel long distance and it is well known for being mobile, high endurance letting it for the user transform to titan for several days or long time of period. When you notice one of the episode on attack on titan showing Pieck walking in quadruped position while greeting Porco it is because of being a cart titan for several months at the secret mission at the Paradis island where their main goal is retrieve the founding titan.
Stay tune for more. Tell me something about your favorite titan and why?