The eggplant crown can be obtained by whipping the eggplant king.
The crown replaces your ability to whip for the ability to toss eggplants, let it be noted you can toss eggplants much faster than you can whip leading it to be powerful ability.
this sometimes proves difficult since a present and an Altar of Kali do not always spawn together on any given floor.
Bringing the fragile eggplant either through waddler or through carrying it through each individual floor, will allow you to sacrifice it upon the purple stained altar of eggplant found in 5-1 ice caves,
the eggplant child largely acts like hired hand in the way it will follow you and fight monster's that are near, except for when picked up and then dropped or placed, upon doing so the eggplant child will fall asleep, doing so will allow the player to continue safely which is crucial to keeping eggplant child alive, and thus continuing the eggplant run
Upon bringing the eggplant child to 7-1 the sunken City the mother statue can be found, placing the eggplant child upon the statues lap will open a secret passage that will take you to the eggplant world.
Upon arriving to the eggplant world you can find the eggplant king at the top of the level, which if whipped will drop the eggplant crown.