Bumbo

Effect

Spawns a familiar which follows Isaac and picks up any nearby coins. Bumbo changes level based on the amount of coins it's collected.

(Collectible Bumbo level 1.png) Level 1 (0-5 coins): Bumbo just collects coins to level up. (Collectible Bumbo level 2.png) Level 2 (6-11 coins): Bumbo occasionally drops a pickup, trinket, chest or pedestal item after a room clear. (Collectible Bumbo level 3.png) Level 3 (12-23 coins): Bumbo now fires tears that deal 3.5 damage in the same direction Isaac does. Bumbo's tears have a chance to drop a coin if they hit an enemy. (Collectible Bumbo level 4.png) Level 4 (24+ coins): Bumbo no longer fires tears and instead chases enemies slowly and deals contact damage (2.5 per tick, or 37.5 per second). Bumbo will occasionally drop bombs while chasing enemies or coins.

After reaching level 4, Bumbo will continue to collect coins, and can drop a pickup, trinket, or chest for each coin it collects, similar to Bum Friend. However, unlike Bum Friend, Bumbo can also drop pedestal items.

Notes

Level 1-3 Bumbo can fly over pits and obstacles, despite having limbs at level 2 and 3 that serve him as legs.
If Bumbo consumes an absurd amount of coins while level four, Bumbo can become level one again [Unsure if bug]
If Level 4 Bumbo targets Mega Satan's head, Bumbo will attempt to "chase" him the entire fight by standing in the middle of the room.
Level 4 Bumbo's bombs are unaffected by Isaac's bomb synergies.
Bumbo cannot pick up Sticky Nickels and will hover over them. Level 4 Bumbo can eventually bomb the Sticky Nickel to free it.
Bumbo will pick up Lucky Pennies, without additional benefit to evolution or drops.
If Bumbo drops a pedestal item, it will be pulled from a random item pool.
Bumbo will not evolve if he takes coins from exploding the Donation Machine.
In a RERUN, Bumbo's level is reset.
Level 4 Bumbo can target charmed enemies and will try to follow them around to no effect. This prevents him from picking up coins until the target is changed.
(Added in Repentance) There is a similar boss named Bumbino.

Synergies

BFFS!: Doubles both the contact and shot damage, when applicable.

Interactions

Box of Friends: Will spawn a level 1 Bumbo regardless of the original Bumbo's current level.
Bum Friend: The bum friend will follow Bumbo instead of Isaac.
(Keeper) Keeper: Not recommended, as the coins Bumbo collects could have been used to heal Keeper.
(Added in Repentance) (Tainted Keeper) Tainted Keeper: Due to the large influx of coins spawned, it's technically possible to sustain Bumbo while also maintaining a good level of wealth and health.

Bugs