Python finally offloads some batteries

A leech is a parasite that latches on to an unwilling host and drains the life out of it to sustain itself. Some metaphor. In fact, the word is specifically used as a particularly emotive term of derision and hatred; it implies that the speaker *utterly despises* the person they're talking about.

Basically, it's a more specific way of describing somebody as a "worthless fucking cunt", or similar. On the offensiveness scale, it's high enough that I can only really think of one word that's higher but that I might occasionally use in close company when senselessly enraged; everything higher than *that* I wouldn't even *think*, let alone say.