You must show your opponent the monster you select from your Deck for this card's effect. If you have no eligible monsters, your opponent gets to see your Deck to verify.

The effect of "Witch of the Black Forest" only activates when she is sent from the field to the Graveyard, not from your hand or Deck, and not if she is removed from play.

If the Summon of this card is negated with "Horn of Heaven" or "Solemn Judgment" you do not get its effect.

If you control your opponent's "Witch of the Black Forest" and it is destroyed, your opponent gets the effect since it activates in his/her Graveyard.

You can chain to the activation of "Witch of the Black Forest's" effect.

Banisher of the Light: Effects that trigger when cards are sent to the Graveyard, such as"Witch of the Black Forest"will not activate.

Bubble Crash: If "Witch of the Black Forest"is sent to the Graveyard, their effects do activate.

Cyber Jar: If "Sangan" or "Witch of the Black Forest" was destroyed by "Cyber Jar's" effect, Special Summon monsters first and then complete "Sangan's" effect.

Dark Ruler Ha Des: Flip Effects and effects that activate in the Graveyard WILL be negated. This includes"Witch of the Black Forest"

Dark Ruler Ha Des: If your Fiend-Type monster battles with "Relinquished" equipped with a"Witch of the Black Forest" and the equipped card is destroyed instead of "Relinquished", the effect of "Sangan", etc., will activate since it was the effect of "Relinquished" that destroyed it. It was not destroyed as a result of battle with the Fiend-Type monster.

Divine Wrath: You can activate "Divine Wrath" to negate an effect that activates in the Graveyard, such as "Witch of the Black Forest"

Doomcaliber Knight: When multiple Effect Monster effects activate simultaneously, "Doomcaliber Knight's" effect is chained after determining the order of the Effect Monster effects (see the Advanced Rulings FAQ "Simultaneous Effects") and will negate the Effect Monster's effect that was placed last on the Chain.
Example 1: Player A Tributes her "Sangan" and "Witch of the Black Forest" to Tribute Summon "Dark Magician". "Sangan's" effect is Chain Link 1 and "Witch of the Black Forest's" effect is Chain Link 2. The effect of Player B's "Doomcaliber Knight" is chained, and it will negate "Witch of the Black Forest's" effect.

Gorgon's Eye: "Gorgon's Eye" cannot negate the effect of"Witch of the Black Forest"because they activate in the Graveyard. If a Defense Position "Slate Warrior" is attacked and destroyed, the effect of "Slate Warrior" that lowers ATK and DEF is applied because it activates in the Graveyard.

Ground Collapse: When resolving the effect of "Cyber Jar" or "Morphing Jar #2", if you pick up more monsters than you can Special Summon, due to "Ground Collapse", the monsters you cannot Special Summon are destroyed. If a "Sangan" or "Witch of the Black Forest" is destroyed this way, its effect does not activate.

Horn of Light: If a"Witch of the Black Forest" equipped with "Horn of Light" is Tributed and you activate the effect of "Horn of Light", "Horn of Light" goes on top of your Deck and then"Witch of the Black Forest" is resolved.

Kaiser Colosseum: When "Kaiser Colosseum" is active, and "Cyber Jar" is activated, if your opponent would control more monsters than you, your opponent has to destroy monsters equal to the difference; the excess monsters are never actually Summoned and instead are sent from the Deck to the Graveyard (so "Witch of the Black Forest" does not get its effect, etc.). So the monsters are destroyed after they are picked up, but before any monsters are Special Summoned for the effect of "Cyber Jar".

Light and Darkness Dragon: If you Tribute “Sangan” and “Witch of the Black Forest” to Tribute Summon “Light and Darkness Dragon”, the effect of “Sangan” and “Witch of the Black Forest” form a Chain. “Light and Darkness Dragon” will negate the activation of whichever effect is placed second on the Chain.

Malevolent Nuzzler: If a"Witch of the Black Forest" equipped with "Malevolent Nuzzler" is Tributed and you activate the effect of "Malevolent Nuzzler", "Malevolent Nuzzler" goes on top of your Deck and then "Sangan" or "Witch of the Black Forest" is resolved. If "Sangan" is destroyed (not Tributed) the effects of "Sangan" and "Malevolent Nuzzler" are simultaneous and form a chain.

Mystical Knight of Jackal: "Mystical Knight of Jackal" sends a monster to the Graveyard as a result of battle, and THEN returns it to the top of the deck, so"Witch of the Black Forest"will activate their effects.

Necrovalley: "Necrovalley" will NOT negate effects that are activated when a card is sent TO the Graveyard or that activate IN the Graveyard or that count cards in the Graveyard. So it will NOT negate the effects of"Witch of the Black Forest"

Outstanding Dog Marron: When "Outstanding Dog Marron" is sent to the Graveyard during a chain, its effect is activated after the current chain resolves (just like "Witch of the Black Forest").

Prohibition: If "Prohibition" declares "Witch of the Black Forest", if the declared card is on the field when "Prohibition" resolves, its effect will activate when it is sent to the Graveyard. If the declared card is Special Summoned after "Prohibition" resolves, it "cannot be used", so its effect will not activate when it is sent to the Graveyard.

Relinquished: The selected monster is treated as a Monster Card when it is sent to the Graveyard, so the effects of"Witch of the Black Forest" would activate

Ring of Destruction: If a player Tributes "Witch of the Black Forest" for "Summoned Skull", you can chain "Ring of Destruction" to the effect of "Witch of the Black Forest", in order to destroy "Summoned Skull". If this reduces the player's Life Points to zero, then they cannot use "Witch of the Black Forest's" effect (to retrieve a 5th Exodia piece, for example).

Skill Drain: "Skill Drain" negates the effects of face-up Effect Monsters on the field, but does not negate effects that activate in the Graveyard, such as "Witch of the Black Forest"

The End of Anubis: "The End of Anubis" WILL negate the effects of"Witch of the Black Forest" (even if Tributed to Tribute Summon

Watapon: "Witch of the Black Forest" are all examples of the types of effects that will activate the effect of "Watapon".The latest print of "Witch of the Black Forest" uses Problem-Solving Card Text, which states that the player cannot activate the effects of cards with the same name as the added card for the rest of the turn. This difference is due to a major change in the functionality of "Witch of the Black Forest".