suppermariobroth:

The model used for Yoshi in New Super Mario Bros. Wii has the regular Yoshi proportions that are used for his appearances as a standalone playable character, optimized for an upright pose. However, with Yoshi’s forward-leaning “rideable” pose in that game, his saddle clips into the spines on the back of his head. To hide this issue, all official art of New Super Mario Bros. Wii uses a modified Yoshi with the saddle moved closer to the tip of his tail.