Thundermare

Creature - Elemental Horse 5/5, 5R (6)
Haste (This creature can attack the turn it comes under your control.)
When Thundermare comes into play, tap all other creatures.¹
It's hooves strike lightning and the thunder follows quickly after.
Illus. Bob Eggleton

Crystal Keep Rulings Summaries

• Note - Also see Comes Into Play Abilities, Rule 410.10a.
• Note - Also see Haste, Rule 502.5.
• Note - The Portal version had no creature type. Then it was of type "Thundermare" until Oracle 2007/05/01 when it became "Elemental". Then with Oracle 2007/10/01 it became "Elemental Horse".

Format Legality	Legal in Vintage, Legacy, Extended Banned in Standard
Printings (3/20)	Core Set - Ninth Edition (Rare) Weatherlight (Rare) Portal (Rare)