Is Generous Pup legal in Standard, Modern, and Commander?

Generous Pup is legal in: Legacy, Vintage, Commander, Historic.

Generous Pup

Q: What type of card is Generous Pup?

Generous Pup is a Creature — Dog. Its oracle text reads: "Vigilance Whenever one or more +1/+1 counters are put on this creature, put a +1/+1 counter on each other creature you control. This ability triggers only once each turn."

Creature — Dog

Vigilance

Whenever one or more +1/+1 counters are put on this creature, put a +1/+1 counter on each other creature you control. This ability triggers only once each turn.

Set Foundations Jumpstart

Rarity Rare

Mana Value 2

Artist Julia Metzger

Collector # 4

Scryfall Gatherer