Is Phantasmal Mount legal in Standard, Modern, and Commander?

Phantasmal Mount is legal in: Legacy, Vintage, Commander, Pauper.

Phantasmal Mount

Q: What type of card is Phantasmal Mount?

Phantasmal Mount is a Creature — Illusion Horse. Its oracle text reads: "Flying{T}: Target creature you control with toughness 2 or less gets +1/+1 and gains flying until end of turn. When Phantasmal Mount leaves the battlefield this turn, sacrifice that creature. When the creature leaves the battlefield this turn, sacrifice Phantasmal Mount."

Creature — Illusion Horse

Flying<br>: Target creature you control with toughness 2 or less gets +1/+1 and gains flying until end of turn. When Phantasmal Mount leaves the battlefield this turn, sacrifice that creature. When the creature leaves the battlefield this turn, sacrifice Phantasmal Mount.