The Hooked Shortspear can be found in Out of the Abyss, page 224.
You have a +3 bonus to attack and damage rolls made with this weapon. This weapon loses its enchantment bonus permanently if it is exposed to sunlight for 1 hour or longer.
On a hit with this weapon, the wielder can forgo dealing damage and attempt to trip the target, in which case the target must succeed on a Strength saving throw or fall prone. The DC is 8 + the wielder's Strength modifier + the wielder's proficiency bonus.
A light weapon is small and easy to handle, making it ideal for use when fighting with two weapons.