Is Flow of Maggots legal in Standard, Modern, and Commander?

Flow of Maggots is legal in: Legacy, Vintage, Commander.

Flow of Maggots

Q: What type of card is Flow of Maggots?

Flow of Maggots is a Creature — Insect. Its oracle text reads: "Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)Flow of Maggots can't be blocked by non-Wall creatures."

Creature — Insect

Cumulative upkeep (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)<br>Flow of Maggots can't be blocked by non-Wall creatures.