Cheapest priced copy (Secrets of Strixhaven Commander): $0.49 at Card Kingdom, near mint, their price list as of .
Renegade Bull 
Creature — Ox · 0/5 · Rare · Secrets of Strixhaven Commander · #36
Trample
Whenever you cast an instant or sorcery spell, this creature gets +X/+0 until end of turn, where X is that spell's mana value.
Whenever this creature attacks, exile up to one target instant or sorcery card from your graveyard and copy it. You may cast the copy without paying its mana cost.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
2 printings · $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Secrets of Strixhaven Commander | 36 | Rare | $0.49 | — |
| Secrets of Strixhaven Commander | 84 | Rare | $0.49 | — |
7 rulings from Wizards of the Coast
- 20 March 2026Renegade Bull's second ability resolves before the spell that caused it to trigger. It resolves even if that spell is countered or otherwise leaves the stack without resolving.
- 20 March 2026A spell's mana value is determined only by its mana cost. Ignore any alternative costs, additional costs, cost increases, or cost reductions.
- 20 March 2026If you cast a spell "without paying its mana cost," you can't choose to cast it for any alternative costs. You can, however, pay additional costs. If the card has any mandatory additional costs, you must pay those to cast the spell.
- 20 March 2026You cast the copy while Renegade Bull's last ability is resolving and still on the stack. You can't wait to cast it later in the turn.
- 20 March 2026If you don't want to cast the copy, you can choose not to; the copy ceases to exist the next time state-based actions are checked.
- 20 March 2026If the spell you cast has {X} in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost.
- 20 March 2026For spells on the stack with {X} in their mana costs, use the value chosen for X to determine the spell's mana value.