A few tool upgrades that came to my mind:
1. Axe of Regrowth upgrade with Chlorophyte Bars
2. Trimarang upgrade with Hellstone Bars
3. Gravedigger's Shovel upgrade with Hallowed Bars
4. Finch Staff upgrade with Feathers
5. Umbrella upgrade with Spectre Bars
6. Breathing Reed upgrade with Chlorophyte Bars
7. Lawn Mower upgrade with Luminite Bar (can mow any type of grass)
1. Axe of Regrowth upgrade with Chlorophyte Bars
2. Trimarang upgrade with Hellstone Bars
3. Gravedigger's Shovel upgrade with Hallowed Bars
4. Finch Staff upgrade with Feathers
5. Umbrella upgrade with Spectre Bars
6. Breathing Reed upgrade with Chlorophyte Bars
7. Lawn Mower upgrade with Luminite Bar (can mow any type of grass)