My most recent cacti is a brain cacti (mammillaria enlongata cistata) 

in terms of care currently it is winter in Australia so in the winter months the tag has directed me not to water so I’m just leaving it be keeping a regular eye on it to make sure it has enough sun and soil to keep it happy 

It is an indoor cacti I was drawn to it for a few reasons I saw one years ago and never stopped thinking about how quirky it was so when I found on at the grocery store I bought it immediately but it is also slow growing and low maintenance which is great because I’m just learning to garden and it is beginner friendly also I can keep it in the skull pot for a while to come since it grows at a slow pace (10-15cm in 5-10 years)