Megatheriums are a popular choice for the Gamma Broodmother, especially when paired for mate boosting and supported by a Yutyrannus for buffs and a Daeodon for healing. Raise health and melee on your fighters, and prioritize strong stamina on the Yutyrannus so it can maintain its support effects. Alternative strategies include using Rexes, wolves, or a solo kangaroo-and-shotgun setup, so choose a strategy that fits your available creatures and playstyle.