Line a 7- by 9-inch loaf pan (9-cup capacity) completely with two or three pieces of plastic wrap, leaving several inches of plastic overhanging on all sides.
Spread strawberry ice cream in an even layer in the bottom of lined pan; freeze for 30 minutes. Spread pistachio ice cream in an even layer over strawberry; freeze for 30 minutes. Spread chocolate ice cream in an even layer over pistachio; cover with overhanging plastic wrap and freeze until firm, about 8 hours, or up to 1 week.
Unwrap terrine and invert pan over a serving plate. Hold on to plastic wrap and lift off pan. Remove plastic wrap. Return to freezer for up to 2 hours, or serve at once. To serve, cut terrine into 1-inch-thick slices (dip knife in hot water and wipe dry between each slice).