Rabid Horseman is a Beast-Warrior Fusion Monster with Attribute EARTH, Level 6, ATK 2000, DEF 1700.
Fusion Summons typically need listed materials and a Fusion method (Polymerization, contact, etc.).
On the current TCG and OCG Forbidden & Limited lists tracked here, Rabid Horseman is Unlimited.
YGOPRODeck lists Rabid Horseman for these formats: GOAT, OCG GOAT, Speed Duel, Duel Links, Common Charity, Edison, TCG, OCG, Master Duel.
A listed print of Rabid Horseman appears in 25th Anniversary Ultimate Kaiba Set (KC01-EN036) at Ultra Rare rarity.
Among markets shown on this page, the lowest listed snapshot for Rabid Horseman is about $0.14 on TCGPlayer (prices change frequently).
