A player fishing with Aqua Pants equipped.
From the Hypixel Pit Wiki

Fishing is an activity in The Pit. It is the only way to obtain certain items, such as Aqua Pants. Players can get fishing rods from the Fishing Rod perk or the Club Rod enchant on Aqua Pants.

Fishing can be done in any body of water, regardless of size.

When fishing without the Fishing Club renown upgrade, the following items can be obtained:

Fishing can be significantly upgraded with the Fishing Club renown upgrade, unlocked at prestige III. Each tier of Fishing Club grants a significant bonus to fishing.