Shark Typhoon

Mana cost: {5}{U}
Type: Enchantment
Set: Ikoria: Lair of Behemoths #319 (rare)
Price: $4.35 USD

Whenever you cast a noncreature spell, create an X/X blue Shark creature token with flying, where X is that spell's mana value.
Cycling {X}{1}{U} ({X}{1}{U}, Discard this card: Draw a card.)
When you cycle this card, create an X/X blue Shark creature token with flying.

Shark Typhoon has 11 printings, first in Ikoria: Lair of Behemoths (2020). EDHREC ranks it #1,232 among Commander cards. It appears most in Aminatou, Veil Piercer decks (12,161 on EDHREC). 3 public decks on TCG run it. It has 6 official rulings.

Legality

commander: legal
legacy: legal
vintage: legal
pauper: not legal
modern: legal
pioneer: legal
standard: not legal
brawl: legal

Public decks that run Shark Typhoon

Miracle Worker - Duskmourn: House of Horror Commander, led by Aminatou, Veil Piercer
Multiverse Reforged - Reality Fracture, led by Jace, Multiverse Architect
Quick Draw - Outlaws of Thunder Junction Commander, led by Stella Lee, Wild Card

Commanders that run Shark Typhoon most

Deck counts from EDHREC.

Aminatou, Veil Piercer: 12,161 decks
Eluge, the Shoreless Sea: 6,279 decks
Jace, Multiverse Architect: 4,928 decks
Y'shtola, Night's Blessed: 4,134 decks
Ashling, Rekindled // Ashling, Rimebound: 3,095 decks
Hinata, Dawn-Crowned: 2,889 decks
Stella Lee, Wild Card: 2,886 decks
Quandrix, the Proof: 2,727 decks

Often played with Shark Typhoon

Cards that show up in the same decks on EDHREC.

Rulings

2020-04-17: An ability that triggers when a player casts a spell resolves before the spell that caused it to trigger. It resolves even if that spell is countered.
2020-04-17: You can cycle a card even if it has a triggered ability from cycling that won't have a legal target. This is because the cycling ability and the triggered ability are separate. This also means that if either ability is countered (with Disallow, for example), the other ability will still resolve.
2020-04-17: Triggered abilities from cycling a card and the cycling ability itself aren't spells. Effects that interact with spells (such as that of Cancel) won't affect them.
2020-04-17: For spells with {X} in their mana costs, use the value chosen for X to determine the spell's mana value.
2020-04-17: Some cards with cycling have an ability that triggers when you cycle them, and some cards have an ability that triggers whenever you cycle any card. These triggered abilities resolve before you draw from the cycling ability.
2020-04-17: You can choose 0 as the value of X in Shark Typhoon's cycling cost. The last ability will trigger, and you'll create a 0/0 blue Shark creature token with flying. Unless something else is raising its toughness, the Shark will then immediately die.