Listed by function, obviously some will have dual functions (Mina and Denn, Wildborn is a trample enabler and additional lands per turn, for instance) so I'll just focus on the primary role.
My only issue is the inconsistency of boom or bust. In that some cards mana ramps up very quickly, others I'm stuck due to a slow start. I feel I may need a few cuts for more slightly more reliable early ramp or card draw (Sol ring, everflowing chalice, Lifecrafter's Bestiary.)
Oh and Hydradoodle has the groups blessing
Decklist
The Hydras
1 Lifeblood Hydra (also draw)
Land ramp (search for lands)
Land ramp (additional per turn)
1 Mina and Denn, Wildborn ( & trample)
Mana doublers/ramp
Card Draw
Boardwipes/one shots
1 Fling
General support/buffs
Approximate Total Cost: