tiger, drunkard
虎 centers on the tiger as a fierce, powerful animal. The extended sense of 'drunkard' likely comes from the image of a wild, unrestrained person, like a tiger on a rampage.
tiger (Panthera tigris)
White Tiger (Taoist god said to rule over the western heavens)
fierce tiger; ferocious tiger
vigilantly (watching for an opportunity); eagerly; with an eagle eye
book of (trade) secrets; secrets
tiger cub
Japanese knotweed (Reynoutria japonica); flowering bamboo
tiger's den; jaws of death; dangerous place
Amur tiger (Panthera tigris altaica); Siberian tiger
mackerel tabby (cat); grey tabby
Siberian tiger (Panthera tigris altaica); Amur tiger
Sumatran tiger (Panthera tigris sumatrae)
Bengal tiger (Panthera tigris tigris)
two equal rivals; two tigers
werecat
common bistort (Persicaria bistorta)
one calamity followed close on the heels of another; out of the frying pan into the fire; tiger in front, wolf in the back
between the devil and the deep sea; out of the frying pan into the fire; a tiger at the front gate, a wolf at the back gate
saber-toothed tiger (sabre)
big tiger
虎 is a pictograph of a tiger, with the modern form retaining a stylized head (虍) and legs/tail (儿). The character has represented the animal since ancient times.
The top part 虍 looks like a tiger's fierce head with stripes, and the bottom 儿 suggests its legs and tail. Together they form a tiger ready to pounce.
For コ, imagine a tiger cub (こ) learning to roar. The little cub (こ) helps you remember the reading コ.