Is Serra Bestiary legal in Standard, Modern, and Commander?

Serra Bestiary is legal in: Legacy, Vintage, Commander, Pauper.

What type of card is Serra Bestiary?

Serra Bestiary is an Enchantment — Aura. Its oracle text reads: "Enchant creatureAt the beginning of your upkeep, sacrifice Serra Bestiary unless you pay {W}{W}.Enchanted creature can't attack or block, and its activated abilities with {T} in their costs can't be activated."

Serra Bestiary

Enchantment — Aura

Enchant creature<br>At the beginning of your upkeep, sacrifice Serra Bestiary unless you pay .<br>Enchanted creature can't attack or block, and its activated abilities with in their costs can't be activated.