Whip

Counts as an additional hand weapon if the bearer is in base contact with an enemy.
In addition, it can be used in a similar way to a spear, allowing the bearer to make one Attack (regardless of the model's number of Attacks) through a rank of Rat Ogres. The same applies to Giant Rats, except that whip armed models can attack over any number of ranks of Giant Rats.
An enemy model cannot attack back against whip-armed models if it is not in base contact with them.