StoryUsed to live at peace with the titan simply avoiding him when neccesary. However after the critters arrived on the island, he was quickly befriended and now the titan has woken, he vows to use all of his knowledge and and experience to help save his new found friends.
StatsHP = 300
Armour = 0
Armour Type = Fortified
Lumber rate = 2 per hit 10 return.
Escape abilities
Lifelong experience - Every 90 seconds the mini titan location is pinged for the user of the builder (mini ping not the alt-click one)

Burrow - The Crab burrows into the ground and becomes invisible. (Moves at reduced speed)
Buildings
Drift wood shelter - Gives +25 food and serves as a lumber drop off point.

Hermit Crab - costs 25 food, Worker unit, 200hp, 25% magic resistance, collects 4 lumber a hit drops off at 40 is 2x2 in size. Has single blink (60sec recharge) and detonate

Ancient Conch - Research centre provides upgrades. Standard stats.

Harden shell - Costs 2000 lumber, grants builder with +1 armour and changes workers armour type to fortified

Health stone - Costs 3000 lumber, Increases the hp of workers by 200

Sharpen Pincers - Costs 1500 lumber, Grants Hermit crab workers with a 25-25 chaos damage attack

Coral Barrier - 250 hp 5 fortified armour, upgrades to enlarged coral barrier with 500hp, 15 fortified armour.(uses coral model) 2x2 spacing

Pebble Tower - Costs, 1 food, 150,250,400(requires research center),500(requires merchant) lumber
Stats, 100,200,300,400 health, 0,1,2,3, fortified armour, 15,30,40,55 damage, 700range for all 2x2 spacing
Merchant - Same as all other builders.
The idea behind this builder was from my friend who is stuggling to get into island defense. The crab builder is very simple with only 4 buildings and 3 researches. His workers take up 2xw spacing to stop seeding as this not only confuses new players but balances out with the lack of fruit trees. The builder has fortified armour and 2 great abilities so it can easily avoid the titan in good hands. However the 'mini' minimap pings are silent and tiny white dots so their very easy to miss. Not to mention in a 30 minute game it will work only 20 times.
The other side of this builder is the ability to be offensive without gold. This is 'hopefully' going to encourage more titans to look for lumber bases and xp as if you camp the gold some nasty crabs will soon be inbound. Not strong enough to kill a titan but ample support for hunters. The workers also give 3 gold to the titan when killed so whilst harder to kill, grant a greater reward.
In short this guy is stupidly simple to use. But in good hands could pottentially really annoy a titan with its survavibility and tough workers.