Effect updates and description changes can be seen here.
Igloo was a card added in Beta 4.8 with a relatively unique ability. Since Beta 12.1, this ability is to summon a random Common, Rare or Epic monster to the board at the start of your turn, including other Igloos. It can't summon generated monsters like Doodlebog. Since Beta 30.0, it also can't summon Basic monsters. This will continue to occur until the board is full or until Igloo is silenced or killed.
No gold is used when cards are summoned, however Magic and Future effects will not initiate as these only occur if placed from the hand to the board. Charges, Dust, and special abilities still work, though. This makes Igloo especially useful in quick drawing aggressive decks, or those who wish to save money whilst taking a risk. Because of the usefulness of this card as well as the chances of you placing a high stats card on the board relatively early on, the Igloo is prone to being a target by the enemy.
As of Beta 8.0.1, summoned monsters will now trigger abilities of monsters that previously only happened whenever the card was placed from hand. Such cards include Politics Bear and Nice Cream Guy, making them good in combo with Igloo.
THIS INCLUDES THEMSELVES!
As a side note, like most cards, if this card is shiny, it will spawn shiny cards.
Igloo has many counters, being very used sometimes.