Is Cryptic Trilobite legal in Standard, Modern, and Commander?

Cryptic Trilobite is legal in: Legacy, Vintage, Commander.

Cryptic Trilobite

Q: What type of card is Cryptic Trilobite?

Cryptic Trilobite is a Creature — Trilobite. Its oracle text reads: "This creature enters with X +1/+1 counters on it. Remove a +1/+1 counter from this creature: Add {C}{C}. Spend this mana only to activate abilities. {1}, {T}: Put a +1/+1 counter on this creature. Power/Toughness: 0/0"