Activate Carrion Feeder by sacrificing Iridescent Drake.
When Iridescent Drake dies, Kaya's Ghostform triggers, returning Iridescent Drake from your graveyard to the battlefield.
When Iridescent Drake enters the battlefield, it triggers, returning Kaya's Ghostform from your graveyard to the battlefield attached to Iridescent Drake.
Resolve the Carrion Feeder ability from step 1, putting a +1/+1 counter on it.