Hello Gabriel,
that is a nice Turbinicarpus viereckii. I do like the ones, which produce pink flowers.
So I went ahead and added it to my "Turbinicarpus spp. wish list".
The last image you state is a "pitahaya". Is that also an Epiphyllum sp.? What is the flower color and does it produce edible fruit?
I do have a large cactus, which does produce a lot of aereal roots and has become quite lanky. It has never flowered and I am starting to have a slight problem to bring the plant indoors over the winter months. My plant may perhaps be the kind which does produce what is commonly called "dragon fruit". Would those also be called "pitahaya" in Mexico?
Harald