Old Gnawbone + Time Sieve

Old Gnawbone
Time Sieve

Requires
Old Gnawbone must be on the battlefield. Time Sieve must be on the battlefield. Old Gnawbone does not have summoning sickness. An opponent is unable to block and kill Old Gnawbone.
Steps
  1. Deal combat damage to an opponent with Old Gnawbone.
  2. Old Gnawbone triggers, creating seven Treasure tokens.
  3. Activate Time Sieve by tapping it and sacrificing five Treasure tokens, causing you to take an extra turn after this one.
  4. Repeat each turn.
Results
Infinite turns.