"Animal Jam" doesn't offer free memberships, as of 2015. The game isn't affiliated with any websites that offer free memberships, and those types of sites can harm "Animal Jam" accounts. You can play "Animal Jam" free of charge, but a membership provides additional benefits.
"Animal Jam" offers one-month, six-month and 12-month membership packages. Longer packages cost more upfront but offer a lower cost per month. The one- and six-month membership packages are recurring, but the 12-month package isn't.
The one-month package includes a 1,500-instant-gem bonus. The six-month package includes a 25-instant-diamond and 9,000-instant-gem bonuses. The 12-month package includes a 60-instant-diamond and 25,000-instant-gem bonuses. Members also get one diamond per week during membership.
All "Animal Jam" players are able to make friends and earn gems by playing games. Members have access to all animals, accessories and dens. Members are also able to adopt and customize all the game's virtual pets, and go to parties and adventures that are members-only.
Player and parent accounts are able to purchase memberships. After logging in to the account, fill out the payment information and confirm the order. If a parent account purchases the membership, that parent is then able to choose which player account receives the membership.