Answers provided by blut_und_glas, Hasran, and yennico himself.
Answers categorized by genre (specific system in one case), with half of the entries going to fantasy ideas.
An Elemental Bull is:
Cyberpunk/Science Fiction (Hasran)
The science of artificial intelligence has made its most significant breakthrough when computer engineers found a way to encode social intelligence, creativity and natural language procession in one sensational algorithm. Named after its creators, the “Levstein-Goldberg-Tangled-Loop” has brought them fortune and fame.
Since it is essential to any practical application of artificially intelligent machines and entities, GoldStein Inc. is the planet’s leading manufacturer and has expanded its portfolio to include everything from dental floss to arms.
The Levstein-Goldberg-Tangled-Loop is also known as “the elemental bull”, because Goldberg and Levstein thought they had encoded a human beings inate ability to lie, deceive and bullshit everybody he or she encounters.
An Elemental Bull is a male elemental, leading a herd of younger females and offspring. Come mating season (which is different for each element), bulls clash with each other and with young contenders who have not yet won a herd of their own.
The fighting of the bulls is the cause of many calamities plaguing the mortal realm – floods in spring (when water bulls have their fights), drought and forest fires in summer (when the fire elementals mate), earthquakes and landslides in autumn (caused by battling earth bulls) and terrible storms in winter (mating season for air elementals).
An Elemental Bull is the primordial spirit of all bull-kind.
It embodies the bull’s characteristics on a spiritual level: strength, virility, determination.
When summoned, the Elemental Bull grants the conjurer both physical as well as mental abilities associated with the bull.
No other Elemental animals have been summoned, which has left the magical communities puzzled and baffled.
Elemental Bull is the name of a superhero with super powers. Elemental Bull can manipulate the elements and wears a horned helmet.
An elemental in the shape of a bull, probably with a similar character, too. Think the Red Bull from the Last Unicorn.
The two prongs of a magical military fork have similarity with the horns of a bull. Because one ability of the magical weapon is to shoot elemental bolts, this military fork is called Elemental Bull.
SLA Industries (blut_und_glas)
Given the “Bull” powersuits I used for the Shade conflict society (SLA Industries), perhaps this is a variant of said powersuit, using elemental weaponry – a flaming sword for example.