toad
蟇 centers on a toad, a specific amphibian. The meaning is concrete and does not branch into abstract extensions.
蟇 combines 虫 (insect/creature) with 莫, which likely contributes the sound. The character specifically denotes a toad.
The top 莫 looks like a squat, bumpy shape, and the bottom 虫 marks it as a creature. Picture a bumpy toad sitting under a broad leaf.
For バ, imagine a toad letting out a deep, croaking 'baaa' sound: baaa -> バ, and the toad's throat puffs out.
toad (esp. the Japanese toad, Bufo japonicus)
Asiatic toad (Bufo gargarizans)
common toad (Bufo bufo)
cane toad (Rhinella marina); marine toad; giant toad
Miyako toad (Bufo gargarizans miyakonis)
Japanese toad (Bufo japonicus); Japanese common toad
Japanese stream toad (Bufo torrenticola)
ranula
toadfish (any fish of family Batrachoididae, esp. the Pacuma toadfish, Batrachoides surinamensis)
large, perforated, turnip-shaped arrowhead cover made of Japanese bigleaf magnolia or paulownia; harmless arrow affixed with such a cover (that whistles when shot and is used to drive off evil spirits)