These include Artifact, Battle, Conspiracy, Creature, Enchantment
It's often losing nothing for being super mana-efficient, and it means this card just becomes a second copy of any card in your deck with a mana value of 4 or less
You can do this to rebuy ETBs or help a creature dodge removal and stuff like that, but you can even just return a land if you just want the Familiar to be a 2/2
Can I print MTG cards from a deck list
While the life loss is a nasty threat, the deathtouch shouldn't be overlooked, as it makes blocking very unpleasant
But making the removal more efficient runs the risk of a deck full of creatures never being able to establish a board in the first place