Worm Demolitions Expert.
Recommended Level-Ups: If you use him a lot, Regeneration first for sure. Take Aim would be of similar value, as it makes him more powerful to use. If he's for abilities, Demolitions is of greatest importance. Boom Shot goes last for its drawback: It can knock back a lot of enemies, but it can easily knock enemies out of an abilities radius.
Recommended Basic Loadout: Bayonet, Grenade, Tremor Bomb, Riot Gear, Nuke
Recommended Advanced Loadout: Grenade (short cooldown, great knock back), Explosive Ammo (aim carefully to get the biggest chaos), Kamikazi (doesn't kill himself!), Claymore (In the right place and at the right time, this will own) and Nuke (make sure you know that the situation actually needs it)
worm is wearing an autocannon--lots of claymores in front of the stash!
Dev Description: "One of the upcoming heroes -- Worm, a guerrila fighter with a variety of explosives and equip-able weaponry!"
Description: Worm, the Demolitions Expert, is a very weak hero health-wise, but with powerful timing-based abilities. He comes in the DLC "Locked 'n' Loaded" and his alt is Slug. Worm's MK Rifle's attack is exremely weak against individual targets but very effective against groups, because it can go through enemies and may damage many bugs in a line. Though he has only 400 health on easy, he regenerates like crazy. To make it fair for the other heroes, you must have Worm active to regen. On the abilities side, Worm has several explosive abilities that require timing to use corectly, such that you must wait a short time before it activates. His abilities are then conversely more powerful than their normal counterparts. Here are his level-up skills:
Regeneration (greatly increases health regen), Boom Shot (increases the chance for bullets to explode on impact, knocking back enemies), Demolitons (increases the damage of all of his explosive abilities) and Take Aim (increases damage while firing without not moving).
Reinforcement: http://bugheroes.wikia.com/wiki/Slug