Ratadrabik of Urborg | Boonweaver Giant | On Serra's Wings

(and one other card)

Activate
Phyrexian Altar by sacrificing
Boonweaver Giant, adding one mana of any color.
When
Boonweaver Giant dies as a legendary creature due to
On Serra's Wings,
Ratadrabik of Urborg triggers, creating a token copy of
Boonweaver Giant that is a 2/2 Zombie in addition to its other types.
When the
Boonweaver Giant token enters the battlefield, it triggers, returning
On Serra's Wings from your graveyard to the battlefield attached to the token.
Repeat.