Lucid Dreams

Card types that can appear on cards in a graveyard include artifact, battle, creature, enchantment, instant, kindred, land, planeswalker, and sorcery. Legendary, basic, and snow are supertypes, not card types; Vedalken and Wizard are subtypes, not card types.

Lucid Dreams is still on the stack and not in your graveyard as you calculate the value of X.

A card can have more than one type. For example, an artifact creature in your graveyard counts as both types for Lucid Dreams' effect.