Ratadrabik of Urborg + Gollum, Patient Plotter + Phyrexian Altar

Ratadrabik of Urborg

Gollum, Patient Plotter

Phyrexian Altar

How it works

1. Activate Phyrexian Altar by sacrificing Gollum, adding one mana of any color.
2. When Gollum dies, it and Ratadrabik trigger.
3. Resolve the Ratadrabik trigger, creating a nonlegendary token copy of Gollum that is a 2/2 Zombie in addition to its other types.
4. Resolve the Gollum trigger from step 2, causing the Ring to tempt you, and for the Gollum token to become your Ring-bearer, thus making it legendary.
5. Repeat.