Eureka originates from the Ancient Greek word εὕρηκα heúrēka, meaning "I have found (it)."
Its description is a reference to its ability.
Statistics
Classes: Brainy, Crazy
Tribes: Mustache Science Superpower Trick
Ability: Conjure any three cards.
Set - Rarity: Premium - Legendary
Card description
Professor Brainstorm's ideas are brilliant... totally random, but brilliant.
Update history
Update 1.22.12
Cards Conjured by Eureka now say they are in their statistics.
Strategies
With
Eureka may seem like a great superpower due to the huge card advantage it provides. However, since it relies on randomly Conjuring cards, it can be rather inconsistent in practice, as the cards obtained are unlikely to be useful.
As Professor Brainstorm, not much can be done to make Eureka useful. He can, of course, run Dino-Roar cards like Tankylosaurus and Zombot Dinotronic Mechasaur for it to activate their abilities multiple times, but both of these are equally questionable in effectiveness as well. The same applies for Mad Chemist, who conjures a trick at random.
As Eureka is a trick and conjures cards, anything that specifically counters tricks like Forget-Me-Nuts, Dark Matter Dragonfruit, Sportacus and Black-Eyed Pea will cause it to backfire. It does benefit from Zombology Teacher (reduces cost of it and any conjured tricks) and Dr. Spacetime (reduces cost of all conjured cards). However, these require very situational combinations:
Professor Brainstorm has no natural access to either of these. He can only obtain Zombology Teacher from Unexpected Gifts/Triplication/Cosmic Scientist. Dr. Spacetime can only be obtained with Cosmic Scientist and Triplication. In the rare case where Eureka conjures these cards and Thinking Cap produces another copy, it could be theoretically useful, but the chances are extremely slim.
So in general, it's often advised to ignore any impact Eureka may have over the course of the whole battle.
Against
Little can be done to deter Eureka from being played, since not even Sportacus, Forget-Me-Nuts, Dark Matter Dragonfruit, or Black-Eyed Pea would stop the opposing hero from getting three more cards. As much as it can be helpful, it might end up being useless, so adapting your play is often the way to go beyond the use of anti-trick cards.