Lemon Bread is a card that's useful during the whole game, as long as you have enough cards in your hand. As this monster gets Haste and Taunt when you have 6 or 7 cards in your hand. (It says 5 or more, but it doesn't include Lemon Bread itself, so you need to have at least 6.) It's the first card with the Haste ability. Haste is the same as Charge, but the monster cannot attack the opponent directly on the first turn.
It's a common card, so is able to be summoned by Igloo. It is also an Amalgamate, therefore is summonable by Alphys.
Before Beta 9.1, Lemon Bread was the only monster with Haste. Spider has it now, too. Beta 10.2 also made Pie give Haste.