Abstract: For development of a baby's gross motor skills, a stand-up training aid is used in combination with a water cooler bottle. The aid features a shroud sized and shaped to fit over the water cooler bottle, and one or more accompanying features, selected from among: a mat that is attached or attachable to the shroud to surround the water cooler bottle in a lain position atop to the floor or ground to use the baby's own body weight to anchor the shroud in place, a plurality climbing elements attached to an exterior of the shroud for manual gripping by the baby, ornamental and/or interactive elements attached at or near an upper end of the shroud to attract attention of the baby toward elevated locations, connection elements attached at or near the upper end of the shroud to accept selective coupling of toys or accessories for such elevational attraction purposes.