Excitable Boy
is a metaphor
Diglett is shaped like a capsule, which is split into two parts. One side (the side with Diglett's face) has many spikes. The other side has many holes which the spikes slide into. To dig, Diglett rotates itself very quickly. To attack, the top half detaches and launches at the foe. If Diglett is using Scratch or something, it fires with the spiky part facing the opponent.