Flowerbot

The monster effect "(1): If this card is sent to the GY: Activate this effect. Draw 1 card from your Deck. Then, place 1 card from your hand on top of the owner's Deck" is a Trigger Effect. (This effect is mandatory. It also activates during the Damage Step.)

This effect can be activated even if you have 0 cards in your hand. In that case, you place the card you drew back on top of the Deck.

The process of drawing a card from the Deck and the process of returning a card from your hand to the Deck are not treated as occurring simultaneously.

This effect also activates if "Flabot" is sent to the GY while it is an Xyz Material, or if "Flabot" is sent to the GY from the hand or Deck.