Lhurgoyf

Lhurgoyf's power is equal to the number of creature cards in all graveyards and its toughness is equal to that number plus 1.

Tarmogoyf

Tarmogoyf's power is equal to the number of card types among cards in all graveyards and its toughness is equal to that number plus 1.

Saffi Eriksdotter

Sacrifice Saffi Eriksdotter: When target creature is put into your graveyard this turn, return that card to the battlefield.

Altar of the Goyf

Whenever a creature you control attacks alone, it gets +X/+X until end of turn, where X is the number of card types among cards in all graveyards.
Lhurgoyf creatures you control have trample.

Hans Eriksson

Whenever Hans Eriksson attacks, reveal the top card of your library. If it's a creature card, put it onto the battlefield tapped and attacking defending player or a planeswalker they control. Otherwise, put that card into your hand. When you put a creature card onto the battlefield this way, it fights Hans Eriksson.