Is Trollhide legal in Standard, Modern, and Commander?

Trollhide is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Pauper.

What type of card is Trollhide?

Trollhide is an Enchantment — Aura. Its oracle text reads: "Enchant creature Enchanted creature gets +2/+2 and has "{1}{G}: Regenerate this creature." (The next time the creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)"

Trollhide

Enchantment — Aura

Enchant creature

Enchanted creature gets +2/+2 and has ": Regenerate this creature." (The next time the creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)