Activate Phyrexian Altar by sacrificing Headhunter, adding {B}.
When Headhunter dies, Missy's first ability triggers, returning Headhunter from your graveyard to the battlefield face down as a 2/2 Cyberman artifact creature.
Activate Headhunter's morph ability by paying {B}, turning it face up.
Repeat.

Infinite death triggers

Infinite ETB

Infinite LTB

Infinite sacrifice triggers

Missy

Phyrexian Altar

Headhunter

Activate Phyrexian Altar by sacrificing Headhunter, adding {B}.
When Headhunter dies, Yedora triggers, returning Headhunter from your graveyard to the battlefield face down as a Forest land.
Activate Headhunter by tapping it, adding {G}.
Activate Headhunter's morph ability by paying {B}, turning it face up.
Repeat.

Infinite green mana

Infinite landfall triggers

Yedora, Grave Gardener

Combos with "Headhunter"