Its a cheap creature that doubles as artifact or enchantment hate, and its lifegain death trigger helps to pad your life total against aggro
There are a few exceptions, but its only cards that are already not legal in the format
You can also c hoose to play Coram, The Undertaker , who can put cards into play from the graveyard, but his ability is focused on land and spell cards
This includes lands, but also high-mana finishers or planeswalkers that can immediately stabilize your board
If your opponent casts a bigger creature, you cant steal it, so your options are a little worse and you might need to rely on your following spell to answer it, but if your following spell is a Wicked Wolf, for example, no matter what they cast, you could turn it into a 3/3 and then use the Food you created the previous turn with Oko to kill their creature with your Wolf after making it a 4/4