Building trust among members is important to effective team functioning. Have each new member stand on a ledge above the rest of the team. Tell her to fall backward and trust her teammates to catch her. Or, blindfold new members and put them at the beginning of an obstacle course or maze. Pair them with a current team member, who will stand at distance and call instructions about which way to move. New members must successfully reach the end within a set period of time to pass.
Help new team members relax and laugh at themselves. Require each to attend practice in a cartoon character costume or wearing a silly hat. Or, tell them that every time another team member says "or," they must make an animal sound of their choice. You could also split new members into small groups and give them five minutes to create a spirit dance to show their devotion to the team, or require them to participate in a contest to see who can make the ugliest face.
Get new members in shape and promote unity. Create a calendar of exercises that each new team member must complete to pass initiation. Include standard exercises, such as pushups, but also include funny exercises, such as leap-frogging, to inject some humor. You could also pit the new team members against the old in a game such as Capture the Flag or kickball. Make it interesting by handicapping the new members in some way, such as requiring each to carry a medicine ball throughout the game.
Let new team members be "slaves" to current members for a day. They must run errands, carry bags and do whatever the current member asks as long as it is not harmful or illegal. Give it an interesting twist by waking up new team members in the middle of the night and making them clean current members' apartments. You could also require new members to complete community service, such as working in a soup kitchen or picking up trash. For every time a member complains, add another hour of service.