永(えい)劫(ごう)の友(ゆう)情(じょう)

Double team

Whenever you cast an instant or sorcery spell, creatures you control that are Otters and/or enchantments get +1/+1 until end of turn.

When Enduring Friendship dies, if it was a creature, return it to the battlefield under its owner's control. It's an enchantment. (It's not a creature.)