Observant Alseid is a common Enchantment Creature — Nymph card from Theros (THS), collector number 24. Current market price: $0.08 (foil $0.28), TCGplayer market prices via Scryfall.
Bestow {4}{W} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.) Vigilance Enchanted creature gets +2/+2 and has vigilance.