The phrase 'climbs on' can be used to describe someone or something ascending, scaling or ascending onto a higher level or surface. Some synonyms for this phrase include 'mounts', 'ascends', 'clambers up', 'scales' and 'scrambles up'. Other synonyms for 'climbs on' include 'hops on', 'boards', 'alights', 'disembarks' and 'enters'. These synonyms can be used interchangeably based on the context of the sentence or the situation. For instance, someone may climb on top of a hill or a roof, or they may climb onto a bus or a bike. Regardless of the context, there is an abundance of synonyms that can be used to describe this action.