Rootwater Alligator

Sacrifice a Forest: Regenerate this creature.

Frogify

Enchant creature
Enchanted creature loses all abilities and is a blue Frog creature with base power and toughness 1/1. (It loses all other card types and creature types.)

Moonring Island

({T}: Add {U}.)
This land enters tapped.
{U}, {T}: Look at the top card of target player's library. Activate only if you control two or more blue permanents.

Whiptongue Frog

{U}: This creature gains flying until end of turn.

Turn to Frog

Until end of turn, target creature loses all abilities and becomes a blue Frog with base power and toughness 1/1.

Frogmite

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)