Is Timbermare legal in Standard, Modern, and Commander?

Timbermare is legal in: Modern, Legacy, Vintage, Commander.

Timbermare

Q: What type of card is Timbermare?

Timbermare is a Creature — Elemental Horse. Its oracle text reads: "Haste Echo {5}{G} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.) When this creature enters, tap all other creatures."

Creature — Elemental Horse

Haste

Echo (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)