| Challenger | Location | HP |
| Advisor Broo | Play Dice A Roo and he will eventually challenge you | 130 |
| Balthazar | You may already have him! He is random and can be found anywhere on the site | 320 |
| Black Pteri | He is random and can be found anywhere on the site | 89 |
| Boochi | Random; he has to fire his ray gun at you. Even if he misses, you will get him as a challenger. | 15 |
| Brain Tree | Complete a quest from the Esophagor | 70 |
| Cave Chia | Go here and refresh, A LOT!!! | 60 |
| Chia Clown | He's automatic when you sign on for Neopets. He's waiting in the Battledome. | 10 |
| Chiazilla | Go here and refresh, A LOT!!! | 500 |
| Commander Garoo | Go here and keep refreshing! | 120 |
| Count Von Roo | Random. He will bite one of your pets (don't worry, it won't hurt) and then you will get him as a challenger. | 120 |
| Edna | Complete one of her quests | 80 |
| Esophagor | Complete its quest | 53 |
| Evil Sloth Clone | Go here | 85 |
| Flaming Meerca | He's automatic and waiting for YOU in the Battledome! | 50 |
| Ghost Lupe | Go here | 32 |
| Giant Ghostkerchief | Go here | 200 |
| Giant Hungry Malevolent Chomby | Go here. After you have 1 omelette, try to go again and at the page where SabreX says no, keep refreshing until he appears. | 350 |
| Grarrg | Go here | 140 |
| Harry the Mutant Moehog | He's automatic and in the Battledome. | 35 |
| Highland Chia | He used to be available in Maraqua, but no more. Write to TNT and tell them to bring the coward back!!! | 60 |
| Jelly Chia | Go here and refresh | 160 |
| Kasuki Lu | Purchase the Kasuki Lu trading card and while it's in your items, look at it and he will appear as a challenger. | 40 |
| Kauvara | Go here | 70 |
| Koi Warrior | Go here and refresh, A LOT!! | 62 |
| Lava Ghoul | Random | 120 |
| Magnus the Torch | Go here | 95 |
| Meerca Henchmen | Go here and keep refreshing until you get one | 150 |
| Meuka | One of your pets must get the Sneezles or Neoflu through a random event or at the WOE. Then you need to go to Quick Reference and it will appear below your pets. | 75 |
| Mummy | Go here | 44 |
| Mutant Chia | He's no longer available. Write to TNT and tell them to bring the coward back!!! | 50 |
| Pant Devil | Random event on the site or from the WOE (he'll steal something from you, so be careful!) | 21 |
| Plumbeard | Go here | 260 |
| Punchbag Bob | He's automatic and already in the Battledome! | 0 |
| Robo Grarrl | He's automatic and already in the Battledome! | 250 |
| Ryshu | Go here | 250 |
| Sabre X | Go to the Plateau in Tyrannia and try to take 2 omelettes in 1 day, random | 79 |
| Shadow Usul | Random | 150 |
| Snow Beast | Go here and refresh, A LOT! | 300 |
| Snow Faerie | Go here and complete one of her quests | 120 |
| Snowager | Get blasted by him here | 700 |
| Space Faerie | Buy Neopets products and take your Rare Item Code here | 550 |
| Spider Grundo | Go here | 200 |
| Sydney | You must win a Level 3 prize or higher from his kiosk | 84 |
| Tiki Tack Man | Go here | 60 |
| Turmaculus | Go here and try to wake him up. He has to eat your petpet to become a Challenger | 250 |
| Vira | Random | 80 |
| Zafara Rogue | Go here and refresh, A LOT! | 39 |
