Anura Box

Upon inspection, you see that it's just a box filled with twigs and leaves. You have no idea who or what left it behind, but it seems like a regular box, probably meant to keep a small creature of some kind.

The Anura Box is a magical tool for conjuration, changing any item you place inside into a randomly enchanted Frog or Toad summon. Each type of summon has its own special power, listed below. In order to use the Anura Box, an item must be placed inside and given time to change. Warning: Items placed in the box are sacrificed to conjure these anura allies. Once you place an item in the box, remove it from your inventory.  

In combat, a player may spend a free or bonus action to place any 1 item into the box. On that player's next turn, or any future turn, s/he may spend 1 action to roll a d6. The result of this roll will determine the type of Frog or Toad summon they retrieve from the box. Once the summon is used, it is immediately dispelled and removed from the game. In order to use the Anura Box again, a player must place another item in the box. 

Outside of combat, a player may use the Anura Box freely, as long as an item is placed inside. 

Anura Summon Possibilities (Listed by Roll result):

1. Frigid Frog's Breath - The box suddenly becomes extremely cold to the touch. An icy blue frog leaps out of the box and lets out a spray of freezing mist. Each creature in a 25-foot cone must make a DC 18 Constitution saving throw. A creature takes 5d10 cold damage on a failed save and is Petrified in ice. A creature takes half as much damage on a successful one.
2. Giant Toad (ally) - A Giant Toad bursts out of the box and stands by your side, making you wonder how such a big creature fit in such a small box. You summon a Giant Toad ally that will enter initiative immediately after your turn. Giant Toad will remain active until destroyed.
3. Fire-bellied Backfire - The instant you open the Anura Box, a crimson Fire-bellied Frog lets out a plume of flames prematurely. Target Self. Make a DC 18 Dexterity saving throw. Take 5d10 fire damage on a failed save and 1d10 ongoing fire damage. Take half as much damage on a successful one. At the end of each of your turns, a successful DC 15 Constitution saving throw will end ongoing damage.
4. Berzerking Bullfrog - The box begins to shake uncontrollably, and you lose your grip. When the box hits the ground, an enormous, brown bullfrog charges forward. Each creature in a 100-foot line must make a DC 18 Dexterity saving throw. A creature takes 7d10 bludgeoning damage on a failed save and is knocked Prone. A creature takes no damage on a successful one.
5. Hellish Horny Toad - A black horny toad leaps from the box, covered in spikes that are saturated with necrotic goo. One creature within a 25-foot line must make a DC 18 Dexterity saving throw. The creature takes 7d10 piercing damage on a failed save and is Poisoned. The creature takes no damage on a successful one.
6. Torture Toad's Telepathy - Barely lifting the lid, a tiny purple toad hops out of the box. As your enemies begin to laugh at its size, their minds suddenly writhe in agony. Each creature in a 25-foot cone must make a DC 18 Wisdom saving throw. A creature takes 5d10 psychic damage on a failed save, and is Frightened. A creature only takes half as much damage on a successful one.