Frogspawn

Frogspawn is a non-solid block that hatches tadpoles. It is laid by frogs.

Obtaining
Frogspawn is currently unobtainable as an item in Survival mode, even if mined with a Silk Touch tool. When broken, it drops nothing.

Hatching
Frogspawn hatches after several minutes of time, causing 2-6 tadpoles to spawn.

Placement
Frogspawn can be placed only on top of a water source block with air above it.