Layla, Ursine Outlander

When you create one or more tokens, create a 2/2 green bear creature token in addition.

When a creature token enters under your control for the first time each turn, Layla becomes a 4/4 bear in addition to its other types and gains, "When one or more creature tokens you control deals combat damage to a player, create a 4/4 green bear creature token with trample."