Venomancer pets

Varicose Scorpion is the better of the two starter pets (level 3 quest to get your first pet) without a doubt. The only land pets that will out-DPS it are the level 10 Dark Wanderer and the level 19 Seamonster Guardian - and then, only if you don't load the scorpion up with skills to increase its DPS. The alternative starter pet, the Sharptooth Wolfling, has slightly better survivability but is over-all mediocre, and you won't really need better survivability until you hit the level 17 quest to kill darkbreed wolfkin, at which time you should be considering a crystalline magmite, or putting off the quest until level 19 when you can get a glacial walker (which will allow you to solo most of the content (not including boss) in the Cave of Rabid Wolves.)

As a grind/farming alt, go pure mag/arcane; you'll kill the mobs quicker, and the main point of being a venomancer is to, as much as possible, let the pet take the hits, so until you hit AOE bosses you really don't have to worry that much about your personal survivability, and the higher matk (and thus stronger heals) increases your pet's survivability.