Blammo

Friendly. The Blammo is a Friendly; It will gladly follow and assist an adventuring party, but its main objective is to explode. If the Blammo is treated poorly by the adventuring party, or the party does not seem to be aiding it towards its goal of exploding, it will leave to seek out a new band of adventurers. The Blammo will roll its own initiative in combat, and will prioritize attacking the closest hostile creature it can. 

Throwable.  The Blammo can be picked up and thrown by another creature. When thrown this way it is treated like a weapon with the Thrown and Light properties with a range of 60/120 and that deals 1d4 bludgeoning damage on a hit. If the Blammo hits a creature this way, its hit points are reduced to 0, and it dies.

KABOOM! If the Blammo dies, it detonates its internal explosives. All creatures within a 30 foot radius of it must make a DC 16 Dexterity saving throw, taking 10d6 fire damage on a failure and half on a success.

Bonk. Melee Weapon Attack: +2 to hit, reach 5 ft., one target. Hit: 2 (1d4) bludgeoning damage.

Light the Fuse. When using the Dash action, the Blammo may choose to light their fuse. Once their fuse is lit, they gain a permanent +30 movement speed. Three turns after the fuse is lit, the Blammo's hit points will drop to 0 and it will die.

Detonate. When the Blammo successfully hits a creature with an attack, it can choose to reduce its own hit points to 0, and die.